ST. PETERSBURG, April 11 (Xinhua) -- One person was killed and 11 others injured in a gas cylinder explosion Wednesday on a ship at the Almaz shipyard in Russia's St. Petersburg.

The local department of the Ministry of Emergency Situations reported that a gas cylinder exploded during welding operations, with 12 people injured.

One of them died in an ambulance, and 10 were hospitalized. Investigators had questioned witnesses of the explosion.

The explosion occurred on a patrol boat, which was repaired at the border guard service. The ship did not get substantial damage.