BAMAKO, Oct 2 (Reuters) - One U.N. peacekeeper was killed and four more were severely wounded when their convoy hit an improvised explosive device in northern Mali on Saturday, the United Nations" force in Mali said. The bloodshed near the town of Tessalit follows the killing of five Malian gendarmes in an ambush on a mining convoy in southern Mali earlier this week that was claimed by a group linked to al Qaeda. read more Armed attacks by Islamist militants and other groups are common across vast swathes of Mali and its neighbours Burkina Faso and Niger despite a heavy presence of international troops. Thousands of civilians have been killed and millions displaced. "This incident is a sad reminder of the permanent danger that hangs over our peacekeepers," said El Ghassim Wane, the head of the U.N. mission known as MINUSMA, in a statement. The mission has deployed over 13,000 troops to contain violence by armed groups in the north and centre of the country. It has recorded about 255 fatalities since 2013, making it the deadliest of the U.N."s more than dozen peacekeeping missions.