Israeli and Lebanese troops have exchanged gunfire along their tense border, and officials from both sides are blaming the other for the clash.

Lebanon says the shooting Monday happened after Israeli soldiers crossed into Lebanese territory, but Israel says its troops came under fire while working along the Israeli side of the border.

Both sides said no one was wounded in the shooting.

A spokesman for the U.N. peacekeeping force in Lebanon said the incident happened in the Wazzani area, and that peacekeepers immediately responded to prevent any escalation. The mission has launched an investigation of the incident and called on both sides to show restraint.

A U.N. peacekeeping force has been in southern Lebanon since 1978. Its original mandate was to verify a withdrawal of Israeli forces. In recent years it has monitored the southern region following the 2006 Israel-Hezbollah war.