WARSAW, Poland -- A gift that Poland's top police commander received during a recent visit to Ukraine exploded at national police headquarters in Warsaw, causing the commander and a civilian employee to suffer minor injuries, the Polish Interior Ministry said Thursday. The explosion happened in a room next to the office of Gen. Jarosław Szymczyk on Wednesday morning, the ministry said. It did not specify what object the Polish commander had received during the working visit to Ukraine. Szymczyk met with leaders of the Ukrainian police and emergency service on Sunday and Monday, the ministry said.