A Chinese peacekeeper and three civilians with the UN's Mali mission have been killed in two attacks in the northern town of Gao, the UN and China's foreign ministry said Wednesday.

Al-Qaeda's North African affiliate AQIM claimed responsibility for Tuesday's attacks, the US monitoring SITE said.

They came only days after five peacekeepers with the UN mission in Mali -- MINUSMA -- were killed in an ambush in central Mali, fuelling concern over the future of the UN's deadliest active mission.

"The MINUSMA camp... in Gao, was targeted with a rocket or mortar attack," a UN mission statement said of Tuesday's deadly incident.

"According to a preliminary report, a peacekeeper was killed and more than a dozen MINUSMA personnel slightly injured."

A second armed attack on a UN de-mining unit killed "two security guards and an international expert", the statement said.

At least 65 peacekeepers with MINUSMA have been killed while on active service in almost three years, while another four have died in friendly fire incidents, UN figures show.

- 'Grave and outrageous'

Chinese foreign ministry spokeswoman Hua Chunying confirmed a Chinese peacekeeper had died in the northern city of Gao in what she called a "terrorist attack".

"This is a grave and outrageous crime, China strongly condemns it, we call for the UN and Mali to carry out a thorough investigation and bring the perpetrators to justice," she told a press conference on Wednesday in Beijing.

Al-Qaeda in the Islamic Maghreb meanwhile said that fighters from its "al-Murabitoun battalion engaged in a clash with 'Crusader occupation forces'," referring to the UN mission in Mali, SITE said.

The jihadists called it an "epic battle" and said they were "thrashing" the enemy.

Al-Murabitoun, led by one-eyed Algerian militant Mokhtar Belmokhtar, has claimed responsibility for several spectacular and bloody attacks in sub-Saharan Africa.

The UN deployed helicopters to monitor the area and a rapid reaction force was patrolling Gao, MINUSMA said in the same statement.

The UN mission chief Mahamat Saleh Annadif said he was "disgusted by these vicious, cowardly and totally unacceptable attacks.".

Annadif called on the Malian government to track down the attackers and bring them to justice.

"These crimes can no longer be tolerated," he added.

Mali's former colonial ruler France also condemned the attack and said it was "at the side of the Malian authorities and MINUSMA in their efforts to fight terrorism and usher in stability in Mali."

Mali's north has seen repeated violence since it fell under the control of Tuareg-led rebels who allied with jihadist groups linked to Al-Qaeda in 2012.

The Islamists were largely ousted by an ongoing French-led military operation launched in January 2013, but they have since carried out sporadic attacks on security forces from desert hideouts.