BAMAKO, Dec 8 (Reuters) - An explosion on Wednesday in central Mali killed seven United Nations peacekeepers and seriously wounded three others, the U.N. mission said on Twitter. A logistics convoy hit an improvised explosive device between the towns of Douentza and Sevare, an area where groups linked to al Qaeda and Islamic State operate. No group claimed responsibility on Wednesday. U.N. Secretary-General Antonio Guterres strongly condemns the attack against the convoy, spokesman Stephane Dujarric said in a statement. "He calls on the Malian authorities to spare no effort in identifying the perpetrators of these attacks so that they can be swiftly brought to justice," Dujarric said. Mali, one of Africa"s largest and poorest countries, is battling an Islamist insurgency that has flourished despite a nine-year effort by international forces led by former colonial power France to defeat it. The U.N."s peacekeeping mission, known as MINUSMA, has deployed over 13,000 troops to contain the violence in the north and centre of the country. It has recorded more than 230 fatalities since 2013, making it the deadliest of the U.N."s more than dozen peacekeeping missions.