(Adds detail on new envoy for peace talks)
BAMAKO, April 23 (Reuters) - A mine exploded in the northern Malian town of Kidal on Wednesday, seriously injuring a United Nations peacekeeper from Guinea but not affecting a delegation of visiting diplomats, a U.N. spokesman said.
There was no immediate claim for the blast but al Qaeda-linked Islamists who seized northern Mali in 2012 have carried out a series of insurgent-style attacks since they were scattered across the Sahara by a French-led offensive last year.
Olivier Salgado, spokesman for the U.N. mission, known as MINUSMA, said a U.N. vehicle struck a mine near Kidal's airport but the vehicle was not part of the security detail for the Bamako-based diplomats visiting the town, a flashpoint for Tuareg separatism.
Salgado said the peacekeeper was from Guinea's contingent in the U.N. mission.
The ambassadors of Germany and Denmark, a Canadian diplomat and several senior U.N. officials were visiting the town when the explosion occurred but they are all safe, the sources said.
Last year, French troops and air strikes drove the al Qaeda-linked fighters from the towns they occupied. Since then, Mali has held presidential and parliamentary elections and U.N. peacekeepers have deployed across much of the vast desert zone.
Pockets of Islamists still carry out sporadic attacks and the lack of progress in talks with local Tuareg and Arab rebel groups is stoking tensions.
President Ibrahim Boubacar Keita on Wednesday named former prime minister Modibo Keita to lead peace negotiations with armed groups, according to a cabinet statement that gave no further details. Keita had previously said there would be no talks unless the groups laid down their arms. (Writing by David Lewis and Matthew Mpoke Bigg; Editing by Angus MacSwan)