Eastern Lebanon (CNN) -- At least 39 people were killed in Syria on Tuesday, as government forces took aim at citizens across the country, opposition activists said.
The deaths included 23 people in the opposition stronghold of Homs, according to the Local Coordination Committees of Syria, a network of opposition activists.
Also in Homs, the Syrian military targeted a bridge on the Orontes River near the Lebanese border that was used as a crossing by wounded civilians, dissidents and refugees fleeing to Lebanon, said the Syrian Observatory for Human Rights, another opposition group.
As many as 2,000 Syrians have crossed from Homs province into Lebanon since Sunday, according to Dana Suleiman, spokesman for the U.N. High Commissioner for Refugees in Beirut.
Eight wounded Syrian men crossed into the Lebanese village of El Qaa from Syria on Tuesday, according to a Lebanese Red Cross official. They were taken to hospitals in northern Lebanon by the Red Cross; one of the Syrians died, said the official, who did not want to be named because he is not authorized to speak to the media.
One man, his head bandaged, was sitting up. Another man, his face pale, lay on a stretcher, blood on his abdomen and his arm, from which an intravenous line was connected to a bag.
Most of the wounded refugees who entered Lebanon did so via informal border crossings into the Bekaa Valley to avoid Syrian border authorities, said the official, who added that the total number was not known.
Refugees also fled the northern Syria city of Idlib after a threat of government shelling, according to the Binnish Coordination Committee local opposition group. The Syrian regime had threatened to shell the city of Idlib if Free Syrian Army opposition fighters there did not hand over their weapons, the group said.
Binnish was among the towns where demonstrations against President Bashar al-Assad's regime were taking place Tuesday, the Binnish Coordination Committee said.
Among those killed in Homs on Tuesday were 13 people from two families, who died in what the Local Coordination Committees called "a new massacre" in the countryside near the city's hard-hit Baba Amr neighborhood at the hands of security forces and armed gangs.
The state-run Syrian Arab News Agency reported Tuesday that some families who had fled "armed terrorist groups" in Baba Amr returned home Monday.
Authorities have restored "stability and security" to the neighborhood, SANA said. Public workers were cleaning, performing maintenance tasks, opening roads "and removing the debris left by the terrorists."
Authorities found a weapons factory and equipment, including "an Israeli-like reconnaissance plane" in the neighborhood, believed to have been used by the terrorist groups, the agency said.
Baba Amr endured nearly a month of shelling before rebel forces announced a "tactical retreat" Thursday. An opposition activist reported arrests, rapes and torture after al-Assad's forces moved in.
The regime has sent reinforcements into the city of Homs, the opposition group Avaaz reported Tuesday.
"Several planes have been spotted over Homs, and residents told Avaaz there is widespread fear that regime forces will start shelling Khaldiya, another staunchly anti-Assad neighborhood, akin to the month-long attack on Baba Amr," the group said in a statement.
Homs residents were afraid to leave their homes, as snipers were posted across the city, Avaaz said.
Spain suspended Tuesday activities at its embassy in Damascus. Other countries, including the United States and France, have closed their Syrian embassies.
As the death toll climbs from the nearly year-long government onslaught, the U.S. military's top commander in the Middle East told lawmakers Tuesday that he believes the violence in Syria will worsen.
Al-Assad's forces remain viable, Gen. James Mattis, head of the U.S. Central Command, said at a Senate Armed Services Committee hearing.
"He will continue to employ heavier and heavier weapons on his people," Mattis said. "I think it will get worse before it gets better."
Mattis predicted that al-Assad will retain power "for some time."
Also Tuesday, preliminary discussions began among the five permanent members of the Security Council plus Morocco "about whether there is any possibility of reaching agreement around a potential text that would demand an end to the violence in Syria and demand immediate humanitarian access," said Susan Rice, U.S. ambassador to the world body. "These discussions are just beginning and will continue. If and when it seems there is a basis for a meaningful and viable text, we will propose one to the full Security Council."
Western diplomats said the goal is to bring the Russians and Chinese into the fold by creating a less harsh version of the last resolution, which the two countries vetoed, that would emphasize the humanitarian situation. They said they want the Russians and Chinese to join the call for a "permissive environment" for humanitarian access.
However, the United States and its allies insist the resolution puts the onus on the regime to stop the violence and will not give up on that issue. This is a nonstarter for the Russians and Chinese, who want any resolution to reflect that armed opposition rebels also bear responsibility.
On Monday, Russian Deputy Foreign Minister Gennady Gatilov posted a message on his Twitter page saying the latest version of a draft resolution doesn't pass his muster.
Turkish Prime Minister Recep Tayyip Erdogan called Tuesday for the opening of a humanitarian aid corridor to Syria. In his televised weekly party parliamentary group meeting, he also called for the implementation of an Arab League plan that calls for al-Assad to step down and demands an immediate end to human rights violations and attacks against civilians. The U.N. General Assembly passed a nonbinding resolution last month endorsing the plan.
U.S. Sen. John McCain, R-Arizona, called Monday for the United States to lead an international effort to protect the Syrian population via piloted airstrikes on regime forces.
The Syrian American Council, an organization for Syrians living in the United States, issued a statement supporting McCain's call. SAC Chairman Mahmoud Khattab said airstrikes would amplify the capabilities of the Free Syria Army, a group primarily made up of Syrian army defectors fighting against the regime.
"It took Assad's well-equipped army 27 days of full-scale assault on the Baba Amr district of Homs, which indicates the effectiveness of the FSA and the exhaustion of the Syrian Army," Khattab said in a statement. "Providing military support for the army defectors will further weaken Assad's forces and help topple the regime."
But U.S. Defense Secretary Leon Panetta was noncommittal.
"The secretary is interested in exploring options that could help end the brutal violence in Syria, but he also recognizes that this is an extremely complex crisis," a senior Pentagon official said. "Intervention at this time could very well exacerbate problems inside the country."
House Speaker John Boehner said Tuesday that he doesn't share McCain's view. "Until there's clear direction on what's happening there, involving ourselves at this point in time would be premature," he said.
While officials in the West and elsewhere discussed the crisis from afar, more carnage mounted across Syria.
The Syrian regime consistently has blamed the violence on "armed terrorist groups" and portrayed its forces as trying to protect the public interest and security. The Syrian government says that more than 2,000 security personnel have been killed in the violence, including 12 "martyrs" it said were buried Monday.
CNN cannot independently confirm reports across Syria because the government has severely restricted the access of international journalists. But the vast majority of reports out of Syria indicate al-Assad's forces are slaughtering civilians in opposition hotbeds in an attempt to wipe out dissidents.
The United Nations says that at least 7,500 people have died in the crackdown, while opposition activists put the toll at more than 9,000.
For months, diplomatic efforts have failed to stop the bloodshed. But international leaders haven't given up on diplomacy.
Valerie Amos, U.N. under-secretary-general for humanitarian affairs and emergency relief coordinator, is slated to arrive Wednesday in Damascus for a two-day visit. "My aim is to urge all parties to allow unhindered access for humanitarian relief workers so that they can evacuate the wounded and deliver essential supplies," Amos said in a statement.
She will meet with Foreign Minister Walid al-Moallem and "will pay visits to some areas in Syria," SANA reported.
Amos was denied access last week by the government, which said it was not a "suitable time" to visit, Syrian state-run TV reported.
And Kofi Annan, the former U.N. secretary-general who is now special joint envoy to Syria for the United Nations and the Arab League, will fly Saturday to Damascus, an Arab League official said. He will be accompanied by his deputy, former Palestinian Foreign Minister Nasser al-Kidwa. Their goal will be to persuade al-Assad to stop the killing, the official said.
Meanwhile, almost two weeks after she was killed by a rocket attack in the Baba Amr neighborhood of Homs, the body of American journalist Marie Colvin is expected to arrive Tuesday in the United States, the U.S. Embassy in Paris said.
CNN's Elise Labott, Kareem Khadder, Nic Robertson, Saad Abedine, Rebecca Stewart, Jennifer Rizzo and Salma Abdelaziz contributed to this report.