West African mediators trying to resolve Mali's political crisis on Sunday called for a power-sharing government and a new constitutional court in their latest bid to calm tensions.

The country is in the grip of a political impasse between President Ibrahim Boubacar Keita, and a newly-galvanised opposition which is intent on his resignation.

At least 11 people died over three days of unrest last week following an anti-Keita protest, in the worst political unrest the West African state has seen in years.

After days of talks with the government and the opposition, mediators from the 15-nation Economic Community of West African States proposed that the current ruling coalition make up 50 percent of a new unity government.

A proposed 30 percent should be members of the opposition and the remaining 20 percent from civil-society groups.

The mediators also suggested appointing new judges to the country's constitutional court, to resolve a dispute over the March-April parliamentary election.

ECOWAS mediators led by former Nigerian president Goodluck Jonathan -- finished their mission on Sunday, after having landed in the country on Wednesday.

On Friday, however, Mali's main opposition alliance spurned an offer from the mediators and stuck to its demand that Keita resign.

The June 5 Movement has triggered a show-down with the government over its unflinching demands that Keita quit for perceived failures in tackling the dire economy and Mali's eight-year jihadist conflict.

At a news conference in the capital Bamako on Sunday, Jonathan told reporters that it was not within the remit of ECOWAS to seek Keita's resignation.

"We met with the M5 four times and we couldn't resolve our differences," he said, referring to the June 5 Movement.