During his visit to Ukraine, Poland’s police chief is presented with a grenade. A few days later, it explodes in his Warsaw office. According to a report, the authorities tried to keep the incident secret for a day.

The head of the Polish police, Jaros?aw Szymczyk, was injured in a grenade explosion at his Warsaw office. The projectile that exploded on Wednesday was a gift that the official received during his visit to Ukraine a few days earlier, the Rzeczpospolita newspaper reports. The report also quotes the Interior Ministry. The exact circumstances are still unclear. The ministry only reported the incident a day later.

The grenade exploded in an adjoining room of the office. The Insider newspaper quoted the ceiling of the room below as having been pierced by the force of the detonation. Apparently to attract little attention, General Jaros?aw Szymczyk was taken to the hospital in a civilian car and not in an ambulance, according to the report. He suffered minor injuries. An employee also suffered minor injuries, but did not have to be treated in the hospital.

The grenade was presented to Poland’s top police officer during a working visit to Ukraine, during which he met with Ukrainian police leaders, according to the Interior Ministry, the newspaper further reports. The Ukrainian side had been asked for explanations. Informants told the newspaper that a number of regulations relating to the grenade had been violated. The public prosecutor’s office is now investigating.