ATMA, Syria: The rebel Free Syrian Army said Sunday it now controls most of the war-torn country, a day after announcing it has moved its command center from Turkey to "liberated areas" inside Syria.
U.N. chief Ban Ki-moon and U.N.-Arab League peace envoy Lakhdar Brahimi held talks about Syria on Saturday, agreeing the crisis was "a steadily increasing threat to regional peace and stability," according to a statement.
Brahimi, who was appointed in early September, is due to brief the U.N. Security Council on Monday about his first round of talks with both the regime, including President Bashar Assad, and opposition groups.
The international community's efforts to halt more than 18 months of bloodshed in Syria have so far failed to make any headway, and fighting persisted overnight and on Sunday.
Troops shelled many rebel-held areas, including in and around Damascus, second city Aleppo in the north, neighboring Idlib, the central cities of Hama and Homs, and Daraa in the south, a watchdog said.
Government air strikes destroyed buildings in Daraa, Hama and Homs as well as Deir Ezzor in the east and the northwestern province of Idlib, said the Syrian Observatory for Human Rights.
Apartment blocks in Albu Kamal were targeted as clashes raged in the town on the Iraqi border, said the Britain-based group, which gathers information from a network of activists.
"The insurgents are trying to wrest control of this strategic town" in oil-rich Deir Ezzor as well as a military airport in nearby Hamdan, said the Observatory's Rami Abdel Rahman.
Losing the town would be "a deadly blow for the regime," he told AFP.
In Aleppo, rebels destroyed two fighter planes on the ground in Orm, a rebel commander told AFP, while a correspondent in the city itself said fighting was less intense than past days.
The Observatory gave no early casualty toll for Sunday. It said 150 people were killed across Syria the previous day -- 88 civilians, 30 rebels and 32 soldiers. Another 25 bodies were found in Damascus.
As the fighting continued unabated, Colonel Ahmad Abdul Wahab of the Free Syrian Army said the regime's aerial superiority was the only thing preventing the FSA from taking control of the capital.
"We control most of the country. In most regions, the soldiers are prisoners of their barracks. They go out very little and we can move freely everywhere, except Damascus," Abdul Wahab told AFP.
"With or without outside help, the fall of the regime is a question of months, not years," he said.
"If we had anti-aircraft and anti-tank missiles, we could quickly gain the advantage. But if foreign countries don't give us these, we will still win. It will take longer, that's all."
Wahab, a colonel in the regular army only nine months ago, said his defection was driven by "the magnitude of the crimes of the regime, which is killing its own people."
He said he commands four katibas (battalions) which make up the "Nasser Salaheddine" brigade in Aleppo and the region.
Wahab said he attends daily meetings with FSA leaders in the northern metropolis, where orders are given to him and other battalion commanders.
On Saturday, the FSA said the next step would be to "liberate" Damascus as it announced that it has moved its command base from Turkey to areas it controls inside Syria.
"The Free Syrian Army command has moved into liberated areas of Syria following arrangements made with battalions and brigades to secure these zones," FSA chief Colonel Riyadh al-Asaad said in a video posted on the Internet.
Nearly 80 percent of towns and villages along the Turkish border are outside the control of Damascus, according to the Syrian Observatory.
The opposition Syrian National Council has warned that the deadly conflict which broke out in March 2011 was reaching "a point of extreme gravity" that could trigger higher levels of extremism in neighboring states.
According to the Observatory, at least 29,000 people have been killed since the revolt against Assad's rule erupted. The United Nations puts the toll at more than 20,000.
As the violence raged, a top NATO general said the alliance does not believe military intervention would bring any improvement in Syria's security situation.
Germany's Manfred Lange said the "political process has to be pushed forward, sanctions need to take effect. At the moment, this situation cannot be solved by the military in a responsible way."