"An L-39 Lithuanian military plane collided with a French Mirage jet in the air. The two Lithuanian pilots ejected successfully and were found uninjured," Ieva Gulbiniene, the assistant commander at the Siauliai air base where a NATO air mission is policing the Baltic, told AFP.
"The French military plane landed successfully," she said, adding "the Lithuanian plane has been located."
As all three EU and NATO Baltic states lack the capability to patrol their own airspace, NATO warplanes from various member states including France have provided assistance, which the alliance has mandated through to 2014.
"We regret this incident. We do not know all the circumstances, an investigation has started. We can only state with relief that casualties were avoided. Unfortunately, incidents like this sometimes happen," Lithuanian Prime Minister Andrius Kubilius told journalists on Tuesday.
"The French embassy is in direct contact with the Lithuanian authorities to learn about the exact circumstances of the collision between a Mirage-2000 from the French detachment and one of Lithuania's L-39 jets," the French embassy in the capital Vilnius said on Tuesday.
"The French aircraft, although damaged, was able to land at the Siauliai base," it added.
Lithuania and its fellow Baltic republics Latvia and Estonia, which won independence from the crumbling Soviet Union in 1991, joined NATO as well as the European Union in 2004.
The trio, with a total population of 6.8 million and a professional military of 20,500, have rocky relations with their former master Russia, which only withdrew its troops from their territories in 1994.