An extra 600 German troops will fly into Kosovo on Sunday to reinforce the NATO-led KFOR peacekeeping mission for six weeks, NATO said on Wednesday. A NATO source denied it was a contingency measure in case of unrest triggered by war crimes indictements for prominent ethnic Albanian leaders. NATO said in a statement the deployment was "part of a routine exercise". The reinforcements will be armoured infantry troops of the Panzer Grenadier Lehr Battalion 92. Their arrival will raise KFOR strength in the U.N. administered province to 19,000. Wednesday's statement said they would stay until April 13. "Planned last year, this operation ... constitutes the first phase of a series of missions, which are planned throughout the year," Wednesday's statement said. It is "designed to demonstrate NATO's ability to reinforce," the statement added. The NATO source rejected the notion that the move was motivated by forecasts of violence should the U.N. war crimes tribunal decide to indict Kosovo prime minister Ramush Haradinaj for his role in the 1999 guerrilla war against Serb forces. --More 2043 Local Time 1743 GMT