Damascus, Syria (CNN) -- Syrian security forces and members of a resistance movement comprised of military defectors clashed in the Damascus suburb of Douma, activists groups said Saturday.
But activists disagreed on whether dissidents, including the Free Syrian Army, were in firm control.
The Syrian Observatory for Human Rights said the opposition held all districts of Douma.
Local Coordination Committees in Syria, another opposition activist group, said "rumors" the FSA held the city were not true.
An activist who CNN is not identifying for safety reasons said security forces departed -- but may return.
"This doesn't mean a wholly liberated situation," the activist said. "They expect them to come back."
Security forces opened fire and launched nail bombs on mourners near a mosque in the city, said the LCC. The Free Syrian Army responded and clashed with the regime's army and other forces, the LCC said.
A Douma resident said the FSA had retreated to a base and no one was in control of the city. "They retreat(ed) because they don't want to bring us a disaster," the resident told CNN.
Government security forces were surrounding the area, said the resident, whom CNN did not identify for safety reasons. The resident feared a massacre, perhaps by either side, if the FSA stayed in position.
The Douma Coordination Committee, another dissident group, said reports of liberation of Douma are "only an exaggeration from different parties to justify the attack and storming of the city. This is a strategy used by Syrian authorities through washing her shame of defeat in the area of Zabdani."
Syrian activists said Wednesday that opposition forces had wrested control of Zabadani from government troops.
The coordination committee said five civilians died Saturday when mourners in Douma were attacked by regime "thugs."
CNN cannot confirm the claims by opposition groups of violence and deaths as Syria's government has limited access by foreign journalists.
Deaths mounted and violence raged across Syria on Saturday as Arab League diplomats prepared to discuss extending its monitoring mission.
The number of people found dead in Syria has risen to at least 59 on Saturday, said the LLC.
They include 30 unidentified corpses found at the National Hospital in Idlib and at least 16 victims of a bus explosion. Deaths occurred in other locations, including Douma, Raqqa in the north, Deir Ezzor in the east and Homs in the west, the LCC said.
For more than 10 months, Syria has been engulfed by an anti-government public uprising and a brutal security crackdown against protesters. The United Nations last month estimated well over 5,000 deaths since mid-March. Opposition groups estimate more than 6,000 people have died.
While activists blame the violence on the President Bashar al-Assad's regime, the government says terrorists have been responsible for the bloodshed.
Both sides reported the deadly bus bombing transporting prisoners in Idlib province, in northwestern Syria.
The LCC said the bus went over a mine, killing at least 16 people and wounding many more. The state-run Syrian Arab News Agency reported that "an armed terrorist group" was responsible for the attack, killing 14 people and wounding 26 others.
Besides gunfire in Homs, security forces also fired at activists and residents near the National Hospital in Idlib and made arrests, the LCC said.
The Syrian Observatory for Human Rights said loyalist forces using heavy automatic weapons and army defectors battled in the Idlib town of Karf Nabl in the Zawiya Mountains.
Mohamed Hamado, a Free Syrian Army lieutenant colonel, said civilians moving toward the Turkish-Syrian border were ambushed by Syrian security forces using tanks and armed personal carriers near the town of Kherbeit Al Joz.
The FSA fought with the Syrian army and injured and killed about 24 soldiers, Hamado said. "We then retreated to safer positions."
The purpose of the Arab League's month-long mission was to determine whether the government was adhering to an agreement to end the violence. The mission was scheduled to end lasdt Thursday but the group was negotiating an extension.
The Arab League has called on the al-Assad regime to stop violence against civilians, free political detainees, remove tanks and weapons from cities and allow outsiders, including the international news media, to travel freely around Syria.
The head of the Arab League mission, Sudanese Lt. Gen. Mohammad Ahmad al-Dabi, will submit a report from the field and the monitors' recommendations to the full body Sunday in Cairo.
Members of the opposition Syrian National Council met Saturday with Arab League Secretary-General Nabil el-Araby.
The council has weighed in over the report about the mission. It is demanding that the report document "the atrocities committed by the Syrian regime against civilians in all cities and towns," the group said in a statement.
"We requested (Araby) to raise the Syria file to the U.N. Security Council as soon as possible to protect the lives and dignity of the Syrian people," national council senior official Walid Buni said Saturday. "We will have to wait until the final Arab Monitor's report is discussed tomorrow but we already know what it contains and do not think it reflects the situation on the ground."
Arab League official Ali Jaroush said the mission has gained momentum and that there is "a general inclination" to extend it for another month, Syria's official SANA news agency reported.
Meanwhile, Syria and Lebanon gave different accounts of the Syrian detention of three north Lebanese men on a vessel.
Port authorities seized a "smuggling" boat sneaking into Syrian territorial waters, SANA reported. The three individuals threw boxes into the sea while fleeing to Lebanon, it said. People on five Lebanese boats opened fire, injuring two of the occupants of the "sneaking" vessel, the news agency said.
Lebanon's National News Agency said the three men were fishing when their boat came under Syrian gunfire. It said the men were "kidnapped" and forced into Syrian territories.
CNN's Joe Sterling, Mohamed Fadel Fahmy and Samira Said contributed to this report