Mali has announced the postponement of regional elections scheduled for December to April, amid security concerns following attacks by armed groups.

The announcement comes two days after four UN peacekeepers and a Malian soldier were killed and more than 21 others injured in two separate attacks. The deadly attacks were claimed by the al-Qaeda-linked Nusrat al-Islam wal Muslimeen.

Friday's attacks took place while troops from the UN peacekeeping mission in the country, known as MINUSMA, were carrying out a joint operation with Malian forces near the border with Niger.

"We have decided to reschedule the elections to the month of April 2018 in order to have more time to organise absolutely inclusive elections," Tieman Hubert Coulibaly, minister for territorial administration, said on Sunday.

The West African country is set to hold a presidential election in July, and it is not clear if the delay in the regional polls will have an effect on the vote.

Armed groups seized the country's vast desert north in 2012 before being forced back by French military intervention in 2013. France has 4,000 soldiers in its former colony.

But, over the last two years, armed groups have re-emerged as a major threat to security in Mali and across its vast, porous desert borders in Niger, Burkina Faso and beyond.

The UN mission, which has more than 11,000 troops and was established in 2013, is one of the most dangerous peacekeeping operations in the world, with troops and convoys regularly coming under attack from armed groups.

According to UN figures, more than 146 members of the mission have lost their lives since 2013.

Last month, three UN peacekeepers from Chad were killed when their vehicle hit a landmine. A fourth peacekeeper died later from his wounds.