The vehicle belonged to French troops, though peacekeepers from other countries may have been on board, according to Lt. Col. Knut Peters, a spokesman for the 16,000-strong NATO-led peacekeeping force, KFOR.
"All six were injured; one of them is in serious condition" and being treated at a military hospital, Peters said.
No civilians were involved in the accident, the cause of which was being investigated, he said, without giving further details.
The NATO-led mission in Kosovo is in charge of securing the ethnically divided province, which has been administered by the United Nations since a 1999 bombing campaign forced and end to a crackdown by Serbian forces on ethnic Albanian separatists.
An explosion of household gas occurred in a nine-storeyed apartment building in the city of Shakhty, the Rostov region of Russia. The blast destroyed two storeys of the building