Several explosions on Tuesday shook a school building allegedly occupied by security forces and pro-government militias in Damascus, al-Jazeera reported.

Syrian state TV quoted the school's director as saying that seven people were wounded in the rebel attack, which had inflicted minor damage on the building. The attack took place in a southeastern district of the Syrian capital which has become a key battleground between President Bashar al-Assad’s troops and opposition forces.

Al-Arabiya quoted a rebel commander as saying that seven improvised devices were set off in two explosions at a school used for weekly planning meetings between government militia and security officers. Both the Damascus Revolutionary Council and the Prophet’s Grandchildren Brigades have claimed responsibility for the blasts.

There has been no official confirmation of the number of people injured in the attack, the extent of the damage, or that the school building was being used by pro-government forces.

A similar blast targeting high-ranking government and military officials killed Defense Minister Daoud Rajha and President Bashar al-Assad’s brother-in-law, Deputy Defense Minister Assef Shawkat in July.

The Syrian conflict has claimed up to 20,000 lives according to estimates by various Syrian opposition groups. The UN estimates the death toll at over 18,000 people. The Syrian authorities say 8,000 were killed.