(CNN) -- More than 5,800 people, including 395 children, died in 2011 during the crackdown on protests in Syria, according to an opposition activist group.
The grim tally of "martyrs" from the Local Coordination Committees of Syria totaled 5,862, including 287 prisoners it said were tortured to death. The LCC said 19 doctors and 146 women were among those killed.
The first death in 2012 was an individual who died due to the lack of blood plasma platelets at a hospital, the group said.
The LCC has a network of contacts across Syria.
President Bashar al-Assad in mid-March began the crackdown on anti-government protesters calling for his ouster. The Syrian government blames "armed terrorist groups" for violence during the uprising.
CNN cannot independently verify opposition accounts of violence or reports of deaths and injuries in Syria. Al-Assad's government has restricted access by international journalists.
Two major Syrian opposition groups, meanwhile, have forged a deal that charts a course for democracy if President al-Assad's regime crumbles.
Representatives of the Syrian National Council and the National Coordination Body for Democratic Change in Syria signed an agreement late Friday in Cairo for a transition in a post-Assad era, the NCB said on its Facebook page.
Protesters turned out on Saturday for anti-regime rallies in restive cities, including Homs, Idlib, and Hama, activists said. They occurred as an Arab League fact-finding mission continued its work to determine whether the Syrian government is abiding by a peace agreement to end a brutal crackdown on protesters.
The LCC said at least 13 people died Saturday amid gunfire, a bolstered police presence and massive demonstrations. Seven were killed in Homs. One each was killed in Hama in the west, Banias and Idlib in the northwest, Abu Kamal in the east, Kafar Soseh in Damascus province, and Daraa in the south.
In Douma, outside Damascus, security forces and shabiha, opposition activists' term for people they say are pro-government "thugs," attacked mourners, raided the town's main square and made many arrests, the LCC said.
Security forces in Aleppo province arrested Moussa Al-Moussa, a senior municipal official in the town of Marea. He was charged with protesting and inciting others to protest, the group said.
Several shabiha dressed like the Arab League delegates in Latakia Friday, the LCC said. When a 14-year-old boy approached them to tell them what is happening in the city, he was "brutally beaten."
The opposition groups hope to end such violence, the al-Assad regime's push against demonstrators and the still well-entrenched government's tenacious efforts to maintain its power across the country.
The NCB is a coalition of 15 functioning parties operating in Syria and in exile dominated by pro-democracy liberal, Marxist and Kurdish parties. The SNC has broad support, with a strong Sunni Muslim component and is backed by the Turkish government. Syria is nearly 75 percent Sunni Muslim. Alawites, who dominate in the al-Assad government, number at least 10 percent, according to estimates.
Their efforts to shape Syria's future signals a maturation and a strengthening of the anti-regime forces.
"This is a key step on a road to building an effective opposition that can not only win the support of foreign governments but build a unified military machine that's going to be able to take on a major power," said Joshua Landis, an associate professor and director of the Center for Middle East Studies at the University of Oklahoma.
"What we are watching today is nation building. Major factions within the Syrian political community coming together and agreeing on strategy."
A Syrian National Council official said the deal still has to be signed off by its board.
"This is a political agreement for the transitional phase that ends with true democratic process and ultimately with elections," said council executive board member Walid Buni. "The preliminary points have been agreed upon but it will be presented to the board of the SNC tonight or tomorrow for final approval. An SNC committee will then present it to the Arab League."
The NCB says the agreement is final.
In a statement on its Facebook page, the NCB said the "agreed text sets out the political and democratic rules for the transitional period, and determines the important parameters for Syria's future which aspire to ensure that the homeland and every citizen's rights are treated with dignity, and for the foundation of a civil democratic state,"
The talks between the two groups lasted more than a month. The agreement will be "deposited as an official document" with the Arab League on Sunday in the presence of league Secretary-General Nabil el-Araby, the NCB said.
Khalaf Dahowd, a senior NCB member based in the United Kingdom, said the agreement was signed by the SNC's Burhan Ghalioun and the NCB's Haytham Manna in the presence of people from both groups.
"The reason the SNC has not called it final yet may have to do with internal politics. But the agreement is final," he said.
Dahowd said the agreement serves to unify ranks and create a post-Assad political framework.
He said the agreement calls for the refusal of any non-Arab foreign intervention, an important issue because some Syrians want international intervention to overthrow the al-Assad regime. At present, the Free Syrian Army, a rebel force composed of military defectors who've taken some actions against regime targets, is on the scene.
The deal calls for "protection of civilians with all legitimate means within international law for human rights" and "honors all soldiers who refused to act on orders to kill civilians," Dahowd said.
The agreement also recognizes the suffering, language and history of the country's Kurdish minority and paves the way for a "democratic, parliamentary, pluralistic and power-sharing system."
"It is also a message to friends of the regime, the Russians and the Chinese who have been raising fears that once the Syrian regime falls there will be a civil war and chaos. So in the agreement we say do not have any of these fears. This will also make it easy to gain political (international) recognition," Dahowd said.
Ahmed Hamoudi, general coordinator of a small Egypt-based opposition group called the Syrian Revolution Coordination, said there are "certain reservations" from some opposition people about the agreement's failure to mention putting al-Assad on trial and forbidding military intervention "while the Syrians on the ground are calling for a no-fly zone."
The Syrian Observatory for Human Rights, a British-based opposition activist network, said it supports and encourages "any agreement or decision" that would forge unity, promote democracy and end the bloodshed and suffering.
The Arab League, the United States, the European Union and Turkey have deplored the al-Assad regime's crackdown and initiated sanctions. But Russia and China have stood in the way of a strong U.N. Security Council resolution toward the Syrian government.
Earlier this month, al-Assad agreed to a peace initiative with the Arab League that calls for security forces to withdraw from cities, release detainees and end violence. Part of the agreement calls for Arab League observers to monitor whether the government abides by the initiative.
Journalist Mohamed Fadel Fahmy and CNN's Salma Abdelaziz, Amir Ahmed and Joe Sterling contributed to this report.