Civil defense team members try to rescue people who were trapped under the debris of a Mosque after an aerial attack on a mosque during prayer in the Cina village of Etarib district of Aleppo, Syria on March 16, 2017. [Photo/Agencies]

Most of the slain people were civilians, when the airstrikes targeted the mosque in the town of Jineh in the western countryside of Aleppo province, said the Syrian Observatory for Human Rights.

The death toll is likely to rise as tens of people were wounded, some in critical conditions.

The UK-based watchdog group, however, stopped short of identifying the warplanes which carried out the strikes.

It said that the airstrikes have intensified in general on Thursday against the rebel positions in the western countryside of Aleppo.