A group headed by former al Qaeda fighter Mokhtar Belmokhtar has claimed responsibility for a suicide raid on U.N. peacekeepers in northern Mali in which at least three people were killed.
Mauritanian news website Alakhbar posted an audio statement claiming the attack on behalf of the armed Islamist group al-Mourabitoun.
"We, the Mourabitoun group, announce the martyrdom operation that one of our knights, Ibrahim al-Ansari, undertook at the headquarters of the Nigerien forces," said the low-quality recording, posted on the website on Friday.
Its authenticity could not be verified, but Alakhbar has often posted statements from Islamist militants in Mali.
At least three civilians were killed and nine peacekeepers from Niger were seriously injured in Wednesday's attack on a U.N. base in the town of Ansongo, around 80 km (50 miles) south of the city of Gao.
Al-Mourabitoun was formed by the veteran Algerian jihadist Belmokhtar, who is a target of French forces hunting down armed Islamist fighters in west Africa, after he split from al-Qaeda in the Islamic Magheb (AQIM).
The group also said recently it was behind an attack on a restaurant in Mali's capital Bamako last month that killed five people.
The latest recording said the Ansongo bombing was carried out in reprisal for Niger President Mahamadou Issoufou's participation in a march in Paris following the attack on the French satirical weekly Charlie Hebdo in January.
It also condemned Issoufou for allowing France and the United States to station military forces in Niger.
Neither Mali's U.N. peacekeeping mission MINUSMA nor Niger's government immediately responded to the audio statement.
In a separate incident late on Friday, gunmen attacked a truck convoy operated by a civilian supplier to MINUSMA around 15 kilometres (10 miles) west of Gao, MINUSMA said.
"After stopping the convoy, the attackers shot the drivers in cold blood before setting the trucks on fire," read a statement released on Saturday.
Also, a young boy lost his arm on Saturday when he unwittingly picked up an improvised bomb planted near a garbage dump in Gao, hospital sources said.
Malian soldiers sealed off the area and proceeded to carry out controlled explosions of several other bombs found nearby.
The United Nations has deployed some 10,000 personnel in Mali, which saw its desert north overrun by al Qaeda-linked Islamists in 2012.
A French-led intervention succeeded in pushing them out of major cities and towns a year later, but there remain pockets of insurgents who launch attacks on UN, French and Malian forces as well as civilians.