Ansar al-Islam group and Prophet's Grandchildren Brigade both claimed responsibility on Tuesday for a blast that reportedly injured several people in the Syrian capital of Damascus. 

The explosion hit a military school located near the Palestine branch of Military Intelligence along the highway leading to the Damascus International Airport. 

There are conflicting reports about casualties. Syrian State TV claims that at least 7 people have been injured in the blast while a government official in Damascus says that three people have been injured. 

According to Syrian State Media, two explosive devices were planted by armed terrorist groups in hidden areas in the Students' Hotel and the Theater. 

"Terrorist group" is usually the term used by the regime to refer to insurgents.

Unconfirmed reports say the school had recently been turned into a military intelligence centre, the Washington Post reports.

A video shared by activists reportedly shows smoke rising from the location of the blast.