WARSAW, Dec 18 (AFP) - Poland’s police chief has said the explosion that left him hospitalised last week was caused by a grenade launcher he had received as a gift from Ukraine.

Jaroslaw Szymczyk’s comments to a local radio station on Saturday are the first to reveal details about the explosion that took place at his office in Warsaw on Wednesday.

Poland’s interior ministry, which announced the incident last week, had not confirmed media reports that the explosion had been caused by a grenade launcher.

Szymczyk told Poland’s RMF FM radio station he had received two used grenade launchers as gifts during a visit to Ukraine and that one of them had been turned into a loudspeaker.

“When I was moving the used grenade launchers, which were gifts from the Ukrainians, there was an explosion,” Szymczyk told the private broadcaster.

He said he was moving the launchers into an upright position at the time when the blast occurred.

“The blast was intense. The force of the shot punctured the floor and damaged the ceiling,” he said.

RMF cited a source from the Polish delegation that visited Ukraine as saying the police chief had received the two launchers from officials as presents during visits to the Ukrainian police and emergency services on December 11 and 12.

Ukrainian officials had assured the Polish delegation the launchers were not loaded, the source told RMF.

The Polish delegation took them back to Warsaw by car before leaving them in the back room of Szymczyk’s office, RMF reported.

The explosion left Szymczyk hospitalised with minor injuries but he has since been discharged.

A civilian employee of the Polish police also suffered minor injuries that did not require hospitalisation.

There was no immediate comment from the Ukrainian police or the State Emergency Service of Ukraine.

Polish authorities are now investigating the incident.