(CNN) -- The head of the Arab League said "more audacious steps" are sorely needed to end the bloodshed in Syria.

Secretary-General Nabil el-Araby made the remarks to league foreign ministers after U.N.-Arab League envoy Kofi Annan told the group his proposed April 12 cease-fire, part of a six-point peace plan, has so far failed to take hold.

The ministers huddled in Doha, Qatar on Saturday to discuss ways to keep the Syrian conflict from deteriorating into a full-blown civil war. Their meeting comes a week after a massacre in the city of Houla sparked worldwide outrage.

"We should have a timeline for the peace plan -- this is a must," el-Araby said. "The international community needs to take immediate action after the massacre in Houla and take all necessary measures in order to protect the Syrian civilians."

The crisis in Syria began nearly 15 months ago, when a tough government crackdown on protesters last year spiraled out of control and spawned a national anti-government uprising. The United Nations for months has said more than 9,000 people have died in Syria. But death counts from opposition groups range from more than 12,000 to more than 14,000.

The opposition Local Coordination Committees of Syria said at least 13 people died Saturday.

Annan said the government has the prime responsibility to stop violence and told the ministers he recently urged President Bashar al-Assad "to radically change his military posture."

He told the group that the crisis is "at a turning point" and that "the specter of all-out civil war with a worry sectarian dimension grows by the day." He said thousands of people have been displaced, taking refuge in Syria or in other countries.

There have been "tensions and incidents" over Syria across the border, he said. Fighting has occurred between pro- and anti-government forces in Lebanon.

He said the U.N. mission to monitor adherence to the cease-fire and his six-point plan continues, even though the initiative is not being implemented. At present, there are 291 U.N. military observers and more than 90 U.N. civilians in the mission.

"It is not the job of the monitors to stop the violence -- that is for the protagonists. But if they have the will to stop the fighting, the monitors can help them implement the commitments they make to each other and the international community. This would promote peace and stability and the conditions for a political process," he said.

Annan also criticized Syria for blocking his deputy Nasser al-Kidwa, appointed by the United Nations and the Arab League, from entering the country.

The regime recently made the move because Syria says it recognizes Annan only as a U.N. representative and doesn't want to engage with the Arab League.

The league has suspended Syria's membership because of the violence. The regime now regards the league as hostile to its power and says some of the group's members are helping the anti-government forces.

Annan said the move to block al-Kidwa is "not acceptable and not wise."

"My mandate is clear. I am the joint U.N. and Arab League envoy. The Arab League should be part of any future resolution in Syria," he said.

Annan said he plans to brief the U.N. General Assembly and U.N. Security Council on Thursday on the crisis.

As for Houla, Annan called it a "terrible crime," but said it is one of "many atrocities" in Syria.

The U.N. Human Rights Council on Friday authorized the U.N.'s Independent International Commission of Inquiry on Syria -- which has issued ongoing reports about violence in the country -- to conduct a robust probe into the massacre last week that left 108 people dead, including 49 children.

Opposition activists and residents have said pro-regime forces went house to house, lining up residents and shooting them.

Syria's representative to the Human Rights Council, Faisal al-Hamwi, said he thinks the "terrorists" are linked to groups "whose main motive was to ignite sectarian sedition in a region with a multi-community social fabric," the state-run Syrian Arab News Agency reported.

Sectarian tensions have been high in Houla, which is overwhelmingly Sunni and is surrounded by Alawite and Shiite villages. Al-Assad's regime is dominated by Alawites.

CNN cannot independently confirm death tolls or reports of violence from Syria because the government limits access to the country by foreign journalists.

CNN's Holly Yan, Saad Abedine, Ivan Watson and Elizabeth Joseph contributed to this report.