Two people were killed, two others were injured Monday after an explosion rocked in Azerbaijan's capital Baku, a health ministry official said.

The explosion hit a small cafe in Binagadi district, a suburb of Baku next to a shopping centre.

The injured people were taken to a burn intensive care unit and both were in critical condition, Ministry of Health spokeswoman Safaya Akhmedova said.

Preliminary findings suggest that the explosion was caused by a gas leak.