ZAGREB, Croatia (AP) — Five migrants have drowned while trying to cross the Kupa river on the border between Croatia and Slovenia, Croatian police said on Friday.

An officer who arrived first at the scene jumped into the river, which is called Kolpa in Slovenia, police said. He helped rescue five other people from the river, while the remaining migrants crossed into Slovenia, a statement said.

No other details were immediately available.

Croatia lies on the so-called Balkan land route used by migrants trying to reach Western Europe. People fleeing war and poverty in their countries in the Middle East, Asia and Africa often face perils on their monthslong journeys.