Activists say that a Syrian military airstrike killed at least 13 people and wounded another 20.

The activist collective, the Aleppo Media Center, and the Britain-based Syrian Observatory for Human Rights say military aircraft used "barrel bombs" — crude bombs made from canisters laden with explosives — to strike the Qabr al-Inglizi area in the northern Syrian province of Aleppo on Tuesday.

The Observatory said at least 13 were killed, including two children and a woman, and that the death toll was likely to rise because more people were buried under the rubble.

The Syrian military's use of so-called "barrel bombs" has been widely criticized because they cannot be precisely targeted. They are believed to have killed thousands of civilians.