Thousands of people have been killed in the regime’s crackdown on the anti-Assad revolt, which has turned increasingly militarized in recent months with a growing risk of civil war. The UN says about 400 people have been killed in the last three weeks, on top of an earlier estimate of more than 5,000 killed since March.

The leader of Qatar, Sheikh Hamad bin Khalifa Al-Thani, was quoted Sunday as saying Arab troops should be sent to Syria to stop the deadly violence — the first statements by an Arab leader calling for the deployment of troops inside Syria.

Qatar, which once had close relations with Damascus, has been a harsh critic of President Bashar Assad’s crackdown. The Gulf state withdrew its ambassador to Syria in the summer to protest the killings. Since the Arab Spring began more than a year ago, Qatar has taken an aggressive role, raising its influence in the region.

“The Syrian people reject any foreign intervention in its affairs, under any title, and would confront any attempt to infringe upon Syria’s sovereignty and the integrity of its territories,” the Foreign Ministry said in a statement.

The government says terrorists are behind the uprising — not reform-seekers — and that armed gangs are acting out a foreign conspiracy to destabilize the country.

A Syrian rebel army chief urged the world on Tuesday to protect civilians in Syria, saying Arab peace monitors had failed to curb Bashar's violent response to the revolt against his rule.

Big powers have also proved unable to stop the bloodshed in Syria, where UN officials say more than 5,000 people have been killed and Damascus says its security forces have lost 2,000 dead.

Riad Al-Asaad, Turkish-based commander of the rebel Free Syrian Army, called for international intervention to replace the Arab observer mission, which has just days to run.

"The Arab League and their monitors failed in their mission and though we respect and appreciate our Arab brothers for their efforts, we think they are incapable of improving conditions in Syria or resisting this regime," he told Reuters.

"For that reason we call on them to turn the issue over to the UN Security Council and we ask that the international community intervene because they are more capable of protecting Syrians at this stage than our Arab brothers," Asaad said.

President Bashar, while proffering reform, has vowed to crush his "terrorist" foes with an "iron fist", but Syrians braving bullets and torture chambers appear equally determined to add him to the list of the past year's toppled Arab leaders.

Army deserters and other rebels have taken up arms against security forces.

"Terrorists" firing rockets killed an officer and five of his men at a rural checkpoint near Damascus, and wounded seven others, the state news agency SANA reported on Tuesday, a day after gunmen assassinated a brigadier general near the capital.

Eight people were killed when a bomb hit a minibus on the Aleppo-Idlib road, the Syrian Observatory for Human Rights said.

In Homs, tank fire crashed into the Khalidiya district after a night rally against Bashar there, activists said. YouTube footage showed a crowd dancing at the rally and waving the old Syrian flag used before the Baath Party seized power in 1963.

The British-based Observatory said two people were killed and nine wounded in the violence in Homs.

Activists also reported fighting between rebels and troops trying to edge into Khalidiya, a neighbourhood that is home to Sunni tribesmen and lies next to the Alawite district of Nozha.

Tanks were firing sporadically at the rebel-held town of Zabadani, near the Lebanese border, which has been under attack since Friday, activists said. They added that several soldiers who had tried to defect to the opposition had been killed.

Syrian forces shot dead a man at a roadblock in the restive Damascus suburb of Qatana, they said, and an activist was killed by sniper fire in the northwestern town of Khan Sheikhoun.

The Arab League must decide soon whether to withdraw its 165 monitors, whose mandate expires on Thursday, or keep them in Syria even though they are set to report that Damascus has not fully implemented a peace plan agreed on Nov. 2.

The Arab plan required Syria to halt the bloodshed, withdraw troops from cities, free detainees, provide access for the monitors and the media and open talks with opposition forces.

The League could ask the UN Security Council to act, but until now opposition from Russia and China has prevented the world body from even criticising Syria, an old ally of Moscow.

Western diplomats said a Russian draft resolution handed to the council on Monday did not make clear if Moscow would accept tough language demanded by the West.

Few Western powers favour any Libya-style military action in Syria, which lies in the heart of the conflict-prone Middle East. Bordering Lebanon, Turkey, Jordan, Iraq and Israel, it is allied to Iran and the armed Lebanese Shi'ite Hezbollah group.

The United States, the European Union, Turkey and the Arab League have announced sanctions against Syria, but while these have hurt its economy, they have yet to prompt Assad to change course. Opposition to sanctions from some of Syria's trading partners, notably Lebanon and Iraq, also dilutes their impact.