SAO PAULO, Jan. 15 (Xinhua) -- At least four people were killed and one was seriously injured in an explosion at a shooting club in the city of Manaus, capital of Brazil's Amazonas state, the local fire department reported on Sunday.

The explosion occurred in the morning at the club, located in the western part of Manaus.

According to the fire department, the causes of the explosion are unknown so far, but when emergency services personnel arrived, there was a strong smell of gas.