Presidents from five West African countries arrive in Mali on Thursday to try to negotiate an end to a political crisis that has rocked the country and raised fears it could undermine a regional fight against Islamist militants.

Infuriated by corruption, disputed local election results and army losses to jihadists, tens of thousands of people have taken to the streets, sparking clashes with police in which the United Nations says at least 14 protesters have died this month.

The opposition, a group called M5-RFP whose figurehead is Saudi-trained Muslim cleric Mahmoud Dicko, has said it will not quit until President Ibrahim Boubacar Keita steps down, raising concerns in neighbouring countries of a protracted crisis.

"M5-RFP demands the resignation of Keita or the satisfaction of our demands," which include the establishment of a committee of inquiry into civilian deaths and a transitional government, the group's spokesperson Nouhoum Togo told Reuters on Thursday.

The leaders of Nigeria, Ivory Coast, Senegal, Ghana and Niger will meet with Keita and then Dicko and other opposition leaders at a hotel in the capital Bamako, according to the mission schedule.

The leaders are expected to make a statement before departing early in the evening.

They are acutely aware of the danger a destabilised Mali poses. The landlocked, semi-desert state has been used as a launch pad for groups linked to al Qaeda and Islamic State to attack neighbouring countries including Niger and Burkina Faso.

Still, reaching a solution in such a short space of time will not be easy. Public opposition to Keita hardened after protesters were killed by police in early July.

The M5-RFP rejected mediation measures proposed by a mission from the West African ECOWAS bloc last week, prompting the presidential mission.