A bombing in southern Lebanon has wounded five U.N. peacekeepers, the second blast to target a U.N. convoy in as many months.

Tuesday's roadside blast hit a U.N. patrol of French peacekeepers on a highway at Sidon. Rescue teams took three of the peacekeepers to a hospital for treatment.

No one has claimed responsibility for the attack.

A similar bombing near Sidon in May wounded six Italian U.N. peacekeepers.

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.

Lebanon has experienced turmoil since January concerning a U.N.-backed tribunal investigating the 2005 assassination of former Prime Minister Rafik Hariri.

A Hezbollah-led grouping withdrew from the national unity Cabinet that month due to disagreements about the tribunal. The Shi'ite group and its allies dominate the new Lebanese government formed last month.

In late June, the U.N.-backed court handed four indictments and arrest warrants in the case to Lebanon.

The accused are reported to be members of Hezbollah.

The group denies involvement in the Hariri assassination.