The real number of displaced people is probably much higher. The Syrians have mainly been fleeing the town of Jisr al-Shughour, targeted in a government crackdown.

The US said the "Syrian government's offensive in northern Syria has created a humanitarian crisis".

A White House statement call for the violence to stop, and the International Committee for the Red Cross to be given "immediate, unfettered access to this region".

An eyewitness described a tank attack on a village near Jisr al-Shughour on Friday morning, in which people were killed and crops destroyed.

Syria's government says its forces went into the town to restore order after the deaths of 120 security personnel.

Clashes throughout the country on Friday led to the deaths of at least 32 people.

Hundreds of people have been killed in a crackdown in recent weeks on anti-government protests, which began in March.