ZAGREB, Croatia — A Czech man has been detained in Croatia for allegedly allowing his 9-year-old child to take an explosive device from a military zone which later killed the child, Croatian police said on Friday.

The 46-year-old man on Wednesday entered a restricted military training ground in central Croatia without authorization where he allowed his child to pick up the explosive device and bring it back to the family car, said a police statement.

When the car later broke down along the way, the child took out the explosive device which then exploded, killing the child and wounding three people, the statement added. It was not immediately clear what kind of device the child had found.

Police did not reveal the sex of the child, though some reports said it was a boy.

The father is facing charges of “grave criminal acts against public safety” in connection with “endangering lives and property by a dangerous act or device,” police said.

Croatia, with its Adriatic Sea coastline, is a favorite tourist destination that is packed with visitors from the Czech Republic and other European countries during the summer season. The explosion happened on Thursday in an area close to the central coastal town of Zadar.