Georgian officials say an apparent gas explosion in an apartment building in a Tbilisi suburb has killed at least four people.

The blast, which occurred late on January 16 on the sixth floor of the building, also injured eight other people, with two in critical condition, authorities said.

The building, located in the Did Digomi district, was evacuated. Emergency officials said a gas leak was suspected.

Georgian Prime Minister Mamuka Bakhtadze declared January 17 a day of mourning.