The Arab League has publicly criticised the violence in Syria for the first time, saying Arab states are "angry and actively monitoring" the crisis.

The comments from the outgoing secretary general, Amr Moussa, drew a bitter response from Damascus. Syria's representative at the league described them as "unbalanced and politically motivated".

Mounting international condemnation, however, has done little to slow the onslaught of the Syrian army as it pushes through northern border villages on an operation it claims is cleansing the area of criminal gangs. Residents of the town of Deir Azzor were reportedly bracing themselves on Tuesday night for the arrival of armour and troops from the Syrian military's feared 4th division, commanded by Maher al-Assad, brother of Syrian leader, Bashar al-Assad.

The same division has been in control of the town of Jisr al-Shughour since Friday, forcing most remaining people in the besieged enclave to flee to the nearby mountains bordering Turkey.

Syrian refugees continue to arrive at crossing points into Turkey and some are reported to have told authorities that the army arrested at least 15 people along the way. More than 7,000 refugees are now in southern Turkey and at least 5,000 have fled into Lebanon. Moussa said: "Though their views differ, Arab states are all worried, angry and actively monitoring the current crisis in Syria. What we are hearing and monitoring, about many victims falling, indicates great tumult in Syria ... The situation in Syria should not be left in this state. Continuation of the status quo could lead to what may not be desired ... for Syria."

Syria's envoy, Youssef Ahmad, claimed Moussa was recommending the same sort of military intervention that the Arab League endorsed in Libya three months ago.

"Days before leaving his post, Moussa calls for a kind of foreign intervention in the Syrian affairs, when the Libyan blood, shed by Nato air strikes as a result for a [UN] security council resolution, based, regrettably on an Arab demand in which Moussa's efforts immensely contributed, isn't dry yet," he said.

On the Lebanon-Syria border, few refugees crossed on Tuesday. "The Syrians are keeping people away from the border," said a man in the town of Wadi Khaled, who identified himself as Omar. "It has been like this for many days."

Wadi Khaled is teeming with refugees from towns and cities, especially Hama and Homs, scenes of fierce violence over the last fortnight. "There are at least 5,000 Syrians here," said Omar.

"But it is very difficult for any more to come because the army is stopping them or shooting them."

Syrian troops were clearly visible patrolling a river that acts as an unofficial border. Several Syrian tanks had their turrets pointed towards Lebanon. At an official crossing point further up the road, there was no sign of anyone arriving.