The European Union election observer mission in Senegal urged the West African nation's top legal body on Sunday to explain publicly why it had accepted some presidential bids and rejected others, such as that of world music star Youssou N'Dour.

The Constitutional Council on Friday validated the candidacy of 85-year-old President Abdoulaye Wade and 13 rivals for the Feb. 26 vote, but turned down N'Dour's bid, saying he did not have the required 10,000 signatures of support.

The decision sparked violent protests on Friday night, and the opposition has vowed to make the country "ungovernable" if Wade insists on running for a third term. [ID:nL5E8CS0I9}

Thijs Berman, the head of the EU election observer mission, urged the council, which meets on Sunday to hear appeals, to release the reasons for its decisions, both for candidates whose bids have been accepted and for those who have been rejected.

"A candidate such as Youssou N'Dour, who had thousands of signatures backing his bid rejected, should have access to the files in order to look closely at why they were rejected, that is important," Berman said, speaking on French public radio RFI.

"For now we have the decisions but we don't have the motivations. I think that not only each of the candidates but also every citizen of Senegal has a right to know," Berman said. "It is only by understanding the reasons of the Constitutional Council that the decision could be accepted."

A final decision by the council is expected within days.

After the violent protests, calm returned to the capital Dakar over the weekend, but security has been boosted around the presidential palace, where truckloads of police in full riot gear were deployed, armed with tear gas, grenade launchers and truncheons.

N'Dour has accused Senegal of using security forces to intimidate people after police shoved him and knocked off his spectacles as he tried to visit jailed human rights activist Alioune Tine on Saturday.

"This is becoming more and more a police state, they are even tapping telephones," N'Dour said at a news conference on Saturday. "My answer will be political, even if the threats are, as they were today, to attack me physically."

Senegal's opposition activist group M23, said the council's decision was a "constitutional coup, and a prelude to what will be an electoral coup" and called on citizens to resist Wade's re-election bid.

Wade's rivals say the constitution sets a limit of two terms on the president. But Wade, who came to power in 2000 and was re-elected in 2007, has argued that his first term pre-dated the 2001 amendment establishing the limit.

Senegal's influential Mouride Muslim brotherhood has urged calm, while Wade has appeared on state television to promise free and fair polls.

Senegal is the only country in mainland West Africa not to have had a coup since the end of the colonial era. February's poll, and a possible run-off a few weeks later, are seen as a test of social cohesion in the predominantly Muslim country.