More Syrians flee violence

Gunfire echoes on the streets of Syria's commercial hub Aleppo.

Amateur video that cannot be independently verified shows that fighting here is still fierce as rebels attempt to hold off heavily armed government forces.

The ongoing violence has forced more than 150,000 Syrians to flee to neighbouring countries, which are struggling to deal with the influx of refugees.

On Tuesday, the United Nations, which is helping coordinate relief efforts, said some of the refugee camps have come under attack.

(SOUNDBITE) (English) UNHCR SPOKESPERSON ADRIAN EDWARDS, SAYING:

"In the northern parts of the Wali Khalid area, where several hundred refugee families reside, has been targeted by shelling from the Syrian side of the border two to three times a week."

The U.N.'s emergency relief coordinator Valerie Amos is now in Damascus to discuss possible humanitarian aid.

But refugees at this camp in Turkey say not enough is being done to stop President Bashar al-Assad.

SOUNDBITE) (Arabic) SYRIAN REFUGEE EMAHMAD SAYING:

"The situation is very bad, we ask all the countries why there are not getting involved? I am here more than a year, and my family is still there and I don't know anything about them."

In the meantime, tens of thousands continue to leave Syria, with no end to the violence in sight.