The US has condemned an assault by Syrian troops on the town of Qusayr.

It's claimed that forces loyal to President Bashar al-Assad depended on Hezbollah militants to win the battle which is said to have caused tremendous suffering to those living in the town.

In a statement, the White House also urged the Syrian government to allow aid organizations into Qusayr to help "evacuate the wounded and provide life-saving medical supplies and treatment."

Syrian troops ousted the rebels from the strategic town near the Lebanese border on Wednesday, after a devastating 17-day assault led by Hezbollah fighters from across the border with Lebanon.

Schools under fire

Syrian forces have been accused of shelling schools and interrogating students in a report released by Human Rights Watch.

'Safe No More' says students have been beaten for alleged anti-government activity and classrooms have been turned into military bases, detention centres and sniper posts by both Syrian armed forces and opposition fighters.

Footage released by the group appears to show terrified students in Dael caught up in a shelling raid. 

Warning: the footage below is graphic

Somaya, 14, from Damascus, said she saw government security forces and militia open fire at peaceful student demonstrations.

"They threw me on the ground but I managed to get away," she said. "They shot at us. One girl got shot in her hand. All the girls ran."

According to the children's charity Unicef, at least one in five schools in Syria no longer function.