Syrian warplanes bombed rebel strongholds outside Damascus and near its largest city, Aleppo, Wednesday.

The aftermath of the operation remains unknown, though a Shi'a shrine was reportedly bombed south of the capitol, resulting in an undetermined amount of casualties, the BBC reported.

The military has carried out airstrikes for the fifth consecutive day, which began last Saturday, the day after the government had agreed to a provisional four-day ceasefire in observance of the Muslim holiday Eid al-Adha.

The agreement fell apart soon after after going into effect last Friday, when a car bomb went off in Damascus near Syrian troops, which the military considered a violation of the ceasefire.

More than 400 casualties were reported over the course of the failed ceasefire.

The 19-month-old conflict has claimed over 20,000 lives according to the U.N., while much international criticism has been directed towards on the administration of President Bashar al-Assad over the military’s use of heavy weapons and airstrikes on civilian-populated areas.