Explainer | What's happening in Mali right now?

Mali plunged back into crisis on Monday when military officers detained the interim president, prime minister and defence minister, derailing a transition back to civilian rule after last year`s coup.

The latest events threaten to exacerbate instability in the West African country where violent Islamist groups linked to al Qaeda and Islamic State control large areas of the north and centre.

Following are details on the origins of the crisis and the risks it poses to the region.

WHAT HAPPENED?

President Bah Ndaw, Prime Minister Moctar Ouane and Defence Minister Souleymane Doucoure were taken to a military base outside the capital Bamako, hours after two members of the military lost their positions in a government reshuffle.

Ndaw, a retired colonel, was sworn in as interim president in September after President Ibrahim Boubacar Keita was overthrown by the military the previous month. He was tasked with leading an 18-month transition to new elections.

He has faced a difficult balancing act, with various political factions and the leaders of the coup against Keita all jockeying for political influence.

WHY DID THE MILITARY DO IT?

The military`s ultimate goal was not immediately clear, but its actions came after two of the leaders of last year`s coup, Sadio Camara and Modibo Kone, lost their posts as defence and security minister in a government reshuffle.

A senior former Malian government official told Reuters that the sacking of Camara and Kone was "an enormous misjudgment" and that the military`s actions were probably aimed at restoring them to their posts.

WHY ARE MALI`S NEIGHBOURS AND ALLIES WORRIED?

Mali`s international partners are concerned about the implications for regional security. Groups linked to al Qaeda and Islamic State are based in Mali and have taken advantage of previous bouts of political instability.

After a coup in 2012 ousted then-President Amadou Toumani Toure, al Qaeda-linked insurgents exploited a power vacuum to seize Mali’s desert north.

Since then, international powers, led by France, have deployed thousands of troops and spent billions of dollars to try to stabilise the country. But they have had little success as the Islamists continue to carry out regular attacks on the army and civilians. They also use Mali as a launch pad for attacks in neighbouring countries like Niger and Burkina Faso.

European leaders worry that prolonged regional instability could see more people displaced, fuelling another wave of migration to their shores.

WHAT COMES NEXT?

The United Nations, European Union and regional countries all called for the immediate release of the detained leaders.

A delegation from the Economic Community of West African States (ECOWAS), which negotiated with the junta that seized power last August, was due in Mali on Tuesday.

The EU`s top diplomat, Josep Borrell, said sanctions would be imposed against those standing in the way of the transition.