The Arab League chief said on Saturday the failure of an Arab plan for Syria would lead to catastrophic results and said he was worried by continuing violence there, despite agreement by Damascus to take measures to end the bloodshed.

Syria said on Wednesday it would abide by a plan backed by the Arab League to end seven months of violence triggered by protests against President Bashar al-Assad.

But there has been no sign of any let up. Activists said security forces have killed dozens since the deal was announced. Tanks killed three people and besieged the central city of Homs on Saturday, although Damascus had agreed to pull the army out of residential areas.

'The failure of the Arab solution would lead to catastrophic results for the situation in Syria and the region as a whole,' Arab League Secretary-General Nabil Elaraby said in a statement, referring to the League plan.

He expressed his 'serious worry over the continuing violence' in Syria and 'appealed to the Syrian government over the need to take immediate steps to protect civilians' and to set the country on the course of dialogue.

Elaraby said Arab states wanted avoid 'foreign intervention'.

Arab officials have said they wanted to avoid a repeat of Libya's experience, in which Arab backing for a no-fly zone led to a U.N. resolution that, in turn, prompted Nato to launch an air campaign.

The Arab plan, which Damascus said it backed, called for a national dialogue, a complete halt to violence, the release of prisoners, removing the military presence from cities and residential areas, and allowing the Arab League and media access to report on the situation.

The statement said Elaraby was in contact with members of an Arab ministerial committee, which is headed by Qatar, about the latest developments in Syria related to the Arab plan.

Elaraby said he had received reports in the past two days from Syria's League representative about armed groups involved in 'violent acts and sabotage' in Homs, Hama and other areas.

It said the secretary-general had also met a delegation from the opposition Syrian National Council, led by Burhan Ghalioun.-Reuters