Attacks on religious sites in Syria are raising tensions, Human Rights Watch has warned.

It reports that an armed opposition group destroyed a Shia place of worship in Idlib governorate, while two churches were looted in Latakia.

Witnesses told HRW investigators that the attacks took place after the opposition gained control of the areas and government forces had retreated.

Investigators found evidence of forced entry at the churches and concluded that the motivation may have been theft rather than a religious attack.

Residents of Ghasaniyeh and Jdeideh, two Christian villages in Latakia, told investigators that neighbours were fleeing because of dire humanitarian conditions as well as the fear of armed opposition fighters, and air and artillery strikes by government forces.

Attacks against minority places of worship are occurring despite assurances from some opposition leaders that all Syrians would be protected in the conflict.

HRW says opposition leaders are failing to address the attacks or stop members of their forces from engaging in lootings and kidnappings.

"The destruction of religious sites is furthering sectarian fears and compounding the tragedies of the country, with tens of thousands killed," said Sarah Leah Whitson, Middle East director at Human Rights Watch.

"Syria will lose its rich cultural and religious diversity if armed groups do not respect places of worship. Leaders on both sides should send a message that those who attack these sites will be held accountable."