The head of the Free Syrian Army demanded Thursday that the Arab League pull its observer mission out of the country over its failure to halt almost 10 months of bloodshed.
Colonel Riyadh al-Asaad issued the call after the Arab League turned to the United Nations for help and admitted "mistakes" in the monitoring mission launched less than two weeks ago.
"We hope they will announce that their mission was a failure and that they will be withdrawn," Asaad, who is based in Turkey, said in the telephone interview with AFP in Beirut.
"We call on the Arab League to step aside and let the United Nations take over responsibility as it is more apt to find solutions," he added.
Arab League ministers are to discuss the mission at a Sunday meeting in Egypt, and Colonel Asaad said his group did not want the observers to be sent back to Damascus after that meeting.
"We don't want them back in Syria," he said.
The observers have been in Syria since December 26 trying to assess the implementation by President Bashar al-Assad's regime of a peace accord aimed at ending a fierce crackdown on democracy protests that erupted in March.
The mission has come in for scathing criticism from Syrian democracy activists, who denounced it as "unprofessional."
Meanwhile, Jeffrey Feltman, the US assistant secretary of state for Near East Affairs, was holding talks in Cairo with the Arab League about the Syrian crisis, amid mounting frustration over the unrelenting violence.
His meeting comes as Assad's regime, which accuses the United States of "gross interference" in Arab affairs, said it freed 552 people detained for involvement in unrest and who have "no blood on their hands."
Qatari Prime Minister Sheikh Hamad bin Jassem al-Thani, who heads an Arab League task force on Syria, on Wednesday discussed the deadly protest crackdown with UN leader Ban Ki-moon in New York, Kuwait's KUNA news agency reported.
"We are coming here for technical help and to see the experience the UN has, because this is the first time the Arab League is involved in sending monitors, and there are some mistakes," said Sheikh Hamad, quoted by KUNA.
A UN spokesman said only that Ban and the sheikh "discussed practical measures by which the United Nations could support the observer mission of the Arab League in Syria."
The sheikh would not say what mistakes had been made. Syrian opposition groups say the monitors have been kept under too tight a rein in the country and that hundreds of people have been killed despite the presence of the observers.
"This is the first experience for us. I said we have to evaluate what sorts of mistakes" have been made, said the Qatari prime minister.
"There is no doubt for me. I can see there are mistakes, but we went there not to stop the killing but to monitor."
The Qatari premier said it was Assad's job to stop the killings, which mounted on Thursday with security forces reportedly killing at least five more civilians.
"We need the experience from the UN and we need to see how we can evaluate if they go back, how they will work," said Sheikh Hamad, adding Arab ministers would reassess the crisis at Sunday's meeting in Cairo.
France called on the Arab League to strengthen the mission with help from the United Nations.
"We encourage the Arab League to use all means possible to strengthen this mission so that observers can move independently throughout Syrian territory and have all necessary contact with Syrian civil society," said a foreign ministry spokesman.
The Local Coordination Committees, which organise protests, have labelled the Arab mission as "unprofessional" and said that Assad's regime was finding it easy to deceive its monitors.
"Soldiers wear police uniforms, drive repainted military vehicles and change the names of places, but this does not mean the army withdrew from cities and streets, or that the regime is applying the provisions of the Arab protocol," they said.
The LCC estimate at least 390 people have been killed since the observers began their mission.
The White House has said it is "past time" for the UN Security Council to act, as "sniper fire, torture and murder" were continuing in Syria and the Arab conditions for the regime have been dishonoured.
"We want to see the international community stand together united in support of the legitimate aspirations of the Syrian people," said White House spokesman Jay Carney.
But the Assad regime denounced the United States for "gross interference" in Arab League affairs and "an unjustified attempt to internationalise" the issue.
And, in a bid to show it was implementing the Arab peace roadmap, it announced on Thursday the release of 552 prisoners, taking to almost 4,000 the number freed since the start of November.
Damascus says the violence has been instigated by "armed terrorist gangs" with help from abroad, but its opponents insist their uprising began with peaceful protests inspired by revolts elsewhere in the Arab world.
However, the brutality of the crackdown has seen a growing number of defections from the military, leading to the formation of Colonel Asaad's Free Syrian Army.
A video uploaded Wednesday to YouTube shows a group of FSA fighters apparently meeting in the flashpoint city of Homs with Arab observers dressed in white caps and fluorescent orange vests.
"We're now sitting in Homs with some of the Free officers... to show members of the Arab observer mission that there are no armed gangs; they are officers who deserted the regime of Bashar al-Assad," a participant says in the video, the authenticity of which could not immediately be verified.
The United Nations last month estimated more than 5,000 have been killed in the crackdown since March.
In a statement, the Syrian Observatory for Human Rights said regime forces shot dead a civilian in the Khalidiyeh neighbourhood of Homs city on Thursday and another four were gunned down in the eastern protest hub of Deir Ezzor.