(CNN) -- Anxiety intensified across the volatile Syrian landscape Wednesday, with deadly confrontations erupting in two major flashpoint cities and fearful people fleeing across the Syrian-Lebanese border describing a black cloud of repression.
Syrian military tanks began shelling two residential areas in Homs, killing at least five people; 13 people were slain in Daraa, 11 when tanks destroyed homes and two by sniper fire; and one person was killed in Jasem, according to Ammar Qurabi, chairman of the National Organization for Human Rights in Syria.
This brings the number of slain protesters to 776 since demonstrations began in the middle of March, and the total of those arrested to 9,000, according to figures compiled by his group.
The Interior Ministry on Wednesday put the number of people involved in riot acts at 3,308 from different Syrian provinces. "The rioters were immediately released after pledging not to repeat acts that may harm the homeland and citizens' security," said the state-run Syrian Arab News Agency (SANA).
The ministry had earlier called upon "those who were misled into participating in or committing unlawful acts" to turn themselves in to authorities before this Sunday. Doing so, it said in a statement, would exempt them from punishment.
However, Syrians intent on fleeing over the Lebanese border Wednesday expressed the ongoing fears of citizens who have taken to the streets.
Some at the border were too scared to speak to CNN reporters even off-camera, but others described terrifying ordeals in places like Daraa and Homs.
Reports that security forces were attacking wounded demonstrators inside hospitals have kept many victims from seeking treatment there, some said.
One Syrian said he had defected from the military and was fleeing with his family to Lebanon. He said he had been ordered to work as a sniper in Daraa, but is intent not to do that job again.
"I prefer to live poor and as a refugee in Lebanon with my six children and wife than (to) kill innocent people in Syria," said Abu Zain.
The man said mass defections from the Syrian army were occurring. In one village along the Syria-Lebanon border, an entire brigade of more than 3,000 troops had defected, he said.
One woman told CNN she fled with her eight children because she did not want them to die.
Members of another family of 10 to 12 female relatives and children told CNN they fled Homs because the army crackdown had become "unbearable" over the past week.
Since the unrest started, Syria has consistently blamed armed groups for the violence, and officials have described the protesters as "conspirators" promoting "sedition." Many security personnel have been "martyred," the government said.
The government also said security forces cranked up their fight against "armed terrorist groups" in Homs and Daraa, SANA said Wednesday. Two Syrian soldiers died and five others were wounded Wednesday, it reported.
But activists and protesters dispute the government assertions that armed groups are behind the violence, saying security personnel have been responsible.
CNN has not been granted access into Syria and is unable to independently verify witness accounts.
Witnesses have been describing a bloody crackdown on anti-government demonstrators who have taken to the streets in protest, an outpouring inspired by a slew of domestic grievances amid the Arab Spring -- the calls for freedom sweeping across the region.
The unrest began in the southern city of Daraa in mid-March and spread to other cities, including Homs, Latakia, suburbs of Damascus such as Douma, and Qamishli in the country's Kurdish region.
Last month, President Bashar al-Assad attempted to placate popular concerns by lifting the country's 48-year-old state of emergency and abolishing the state security court, both of which were key demands of the demonstrators.
But anti-government protests have persisted, with activists demanding the immediate release of political prisoners, the lifting of emergency and martial law, and the withdrawal of intelligence forces from Syrian cities.
The international community has condemned the government's actions.
Secretary-General Ban Ki-moon said Wednesday that the United Nations would continue to push Syria to allow an independent humanitarian team access to the cities and towns where clashes have erupted.
He said he was disappointed that Syria has not given the world body the access it has requested, and explained that an assessment mission is important for an effective international humanitarian response to the violence.
"I again urge President Assad to heed the calls of the people for reform and freedom, and to desist from excessive force and (the) mass arrest of peaceful demonstrators," Ban said in Geneva.
The U.N. Human Rights Council has approved a mission to Syria to probe alleged abuses, and Ban urged cooperation with the council.
Meanwhile, Syria has dropped an effort to gain a seat on the U.N. Human Rights Council amid condemnation over its security crackdown.
Syria said it has agreed not to run for a council seat this year. It said it has swapped its candidacy with Kuwait and will run in 2013.
"This election had become a referendum on Syria's violent suppression of protests, and Syria withdrew rather than face a resounding defeat," said Peggy Hicks, global advocacy director at Human Rights Watch.
In Washington, State Department spokesman Mark Toner said officials were looking into reports that government tanks were shelling homes. "But whether they're accurate or not, we can say that these repressive measures, namely the ongoing campaign of arbitrary arrests, the denial of medical care to wounded persons, inhumane conditions of detainees are barbaric measures that amount to collective punishment of innocent civilians," he told reporters.
Toner added that time was running out for Damascus. "The Syrian government needs to realize that its approach is not in the best interests of Syria and the window is narrowing for the Syrian government to shift focus from its outright repression and towards meeting the legitimate aspirations of its people."
Sen. John McCain, R-Arizona, called on U.S. officials to use the bully pulpit to effect change. "It's time for the president of the United States to speak up forcefully and frequently, and the secretary of state, both of whom are listened to throughout the world, to speak up forcefully on this situation," he said. "If Bashar al-Assad is successful through the use of blood and steel to repress the legitimate aspirations of his people, that will be a lesson to tyrants throughout the world."
CNN's Rima Maktabi, Yousuf Basil, Salma Abdelaziz and Joe Vaccarello contributed to this report.