The commander of Syrian armed rebels said on Tuesday he was dissatisfied with Arab monitors' progress in halting a military crackdown on protests and threatened to wait only a few days before escalating operations with a new style of attack.

If we feel they (the monitors) are still not serious in a few days, or at most within a week, we will take a decision which will surprise the regime and the whole world, the head of the Free Syrian Army (FSA), Colonel Riad al-Asaad, told Reuters.

Army defectors and armed rebels, loosely organised under the FSA umbrella, have began assaults on Syrian state forces in the past months, killing hundreds of soldiers in operations they said are meant to defend the uprising's peaceful protests against President Bashar al-Assad.

Asaad told Reuters last week he had ordered a halt to attacks on security forces to give the monitors a chance to operate and prove that it is the regime that is the criminal. The president says his forces are fighting against foreign-backed armed terrorists that have killed 2,000 of his men.

The colonel, speaking by telephone from his safe haven in southern Turkey, said that the monitors' presence in Syria last week had not stemmed the bloodshed.

A Reuters tally based on activist reports shows that at least 129 people were killed in the team's first week. Other activist groups put the toll as high as 390.

What is most likely now is that we will start a huge escalation of our operations, Asaad said.

He said it would not be an outright declaration of war, but it will be a transformative shift in terms of the fighting and we hope the Syrian people will stand behind it.

MISSION

The Arab League began its one-month mission to Syria last week to check whether Damascus was implementing a deal to withdraw troops from cities, speak to the opposition and release tens of thousands people believed to be detained since the uprising against the president began in March.

The secretary-general of the Arab League, Nabil Elaraby, told journalists on Monday that tanks had been withdrawn but that snipers and gunfire continued to be a problem. He said the mission needed more time to work.

Asaad asked: For how long? Since they entered we had many more martyrs. Is it in the Syrian people's interest to allow the massacre to continue?

The colonel also rejected the monitors' assessment that tanks had been withdrawn or that Damascus had shown any willingness to cooperate with the Arab initiative, arguing that tanks were still present on the perimeters of flashpoint cities.

The regime hasn't stopped shooting and killing, they haven't released all the prisoners ... the first order was to send soldiers back to their barracks, not to surround the cities from outside, he said.

The Arab League said it had secured the release of 3,484 prisoners last week. Before the monitors' arrival, human rights group Avaaz estimated that up to 37,000 were in detention.

Asaad said he spoke to one monitor in Deraa but said the mission had yet to respond to his complaints, such as the 1,500 army defectors the FSA believes to be detained.

Despite Asaad saying the FSA had ordered a temporary halt on attacks, at least nine state soldiers have been killed in three attacks, underscoring scepticism that army officers steering the FSA from Turkey are in full control.

Asaad said those operations had all been in self defence.

(Editing by Alison Williams)