Potential UN headquarters attacked in Libyan capital

TRIPOLI, Jan 29 (Reuters) - Unknown assailants threw an improvised explosive on Tuesday at an empty building the United Nations had considered as a possible headquarters of its Libya mission in Tripoli, causing minor damage but no injuries, a mission spokesman said.

There are heightened concerns about Islamist militant attacks in North Africa after a hostage crisis in Algeria and the start of French military operations against jihadist rebels in Mali earlier this month.

Radhia Achouri, spokeswoman for the U.N. Support Mission in Libya, recounting Tuesday's incident, said a second, similar homemade explosive was later found and removed without problem by Libyan police, who were now investigating the matter.

On Monday, the British embassy in Tripoli said it was aware of reports of a potential threat against it, days after London urged British nationals to leave the eastern city of Benghazi due to a "specific and imminent threat" against Westerners. (Reporting by Marie-Louise Gumuchian; Editing by Mark Heinrich)