A Chinese peacekeeper and three civilians working for the UN's Mali mission have become the latest casualties of the troubled outfit, the UN and China's foreign ministry said Wednesday.
The last month alone has seen three attacks on members of the mission, known as MINUSMA, fuelling concern over its future with 65 killed in under three years.
It is the deadliest active deployment for UN peacekeepers.
Al-Qaeda's North African affiliate AQIM claimed responsibility for the latest attacks on Tuesday, the US monitoring SITE said.
The MINUSMA camp was targeted in a mortar or rocket assault, a statement from the mission said, during which "a peacekeeper was killed and three peacekeepers seriously wounded."
A second armed attack on a UN de-mining unit killed "two security guards and an international expert", said the same statement.
It was "the first time a Chinese UN peacekeeper has been killed in the north," an African military source told AFP, adding that of the civilians killed one was French and the two others Malian.
The three peacekeepers seriously wounded were all Chinese, the source added.
The deaths bring to 12 the number of peacekeepers killed in Mali in May alone, UN Secretary-General Ban Ki-Moon's spokesman Stephane Dujarric said.
In other attacks, five Togolese peacekeepers were killed in an ambush by unidentified gunmen in the centre of the country on May 29. Five Chadians died on May 19 when their vehicle hit a landmine and then came under fire by Islamist group Ansar Dine.
Dujarric said Ban was "outraged" by Tuesday's attacks and intended to present the Security Council with proposals "to strengthen the mission's posture and capabilities."
The Security Council condemned the attacks "in the strongest terms".
- 'Outrageous crime' -
Chinese foreign ministry spokeswoman Hua Chunying said the Chinese peacekeeper was killed in 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.
Al-Murabitoun, led by one-eyed Algerian militant Mokhtar Belmokhtar, has claimed responsibility for several spectacular and bloody attacks in sub-Saharan Africa.
MINUSMA chief Mahamat Saleh Annadif called on the Malian government to track down the attackers and bring them to justice.
"These crimes can no longer be tolerated," he said.
Northern Mali has been the scene of repeated attacks since it fell under the control of three radical Islamist groups, including AQIM, in 2012.
The rebels were largely ousted by an ongoing French-led military operation launched in January 2013, but they have continued to mount attacks on security forces from desert hideouts.
Dujarric said that MINUSMA, which deployed in mid-2013, needed to be "adequately equipped" to operate in Mali.
But he poured cold water on suggestions that an intervention brigade like that deployed as part of the UN mission in Democratic Republic of Congo would protect the peacekeepers.
"The threat that we are facing from terrorist groups in Mali is different from what we are seeing in DRC," he said.