More than 160 killed as Syrian rebels try to siege

The death toll is unusually high for such a short period, testifying to the ferocity of the fighting.

It also points to the increasingly sectarian nature of the conflict, with Sunni Muslim radicals bolstering rebel ranks and Shiite militants from Iraq and Lebanon fighting on the government side.

Abdurrahman also said that at least two Syrian media activists were killed as they covered the clashes in eastern Ghouta.