Syrian opposition said they are under fierce regime attacks near the Turkish border despite a cessation of hostilities agreement as US expressed ‘concern’ about regime assaults on civilian areas.

The agreement drawn up by the US and Russia, which came into effect on Saturday, has slowed but not entirely stopped fighting.

The Reuters news agency quoted an opposition official and the Britain-based Syrian Observatory for Human Rights monitoring group as saying that regime forces pressed an offensive against opposition forces in Latakia province at the Turkish border on Wednesday.

Fadi Ahmad, spokesman for the First Coastal Division, a Free Syrian Army group, said regime forces had brought in reinforcements and that fighting was as intense as anything preceding the cessation of hostilities.

"The battles were today very fierce," he told Reuters.

"Battles continue in vital areas that the regime wants, and where there was no truce in the first place. There is bombardment and battles," an opposition commander told Reuters.

"We are in the fifth day and there is no change in these areas," he said, in reference to areas in the provinces of Latakia, Homs and Hama.

There was no immediate comment from Damascus, which has denied breaching the terms of the truce.

Meanwhile, the White House said it had seen a reduction in air strikes against the opposition and civilians in Syria in recent days but was concerned by reported tank and artillery attacks.

"We are concerned about reports that the Syrian regime has engaged in tank and artillery attacks against civilians," White House spokesman Josh Earnest said, referring to reports about strikes near Latakia.

"Obviously those kinds of attacks - if confirmed - would be a flagrant violation of cessation of hostilities."

The opposition is pressing for full humanitarian access to opposition-held areas and for detainees to be released - terms set out in a UN Security Council resolution passed in December.

PHOTO CAPTION

Syrian regime troops ride on a pickup truck with a mounted machine gun on a road near Latakia in Syria, Wednesday, March 2, 2016.

Al-Jazeera