The former Nigerian president, Olusegun Obasanjo, has begun meeting politicians in Senegal in an effort to resolve the West African nation's political crisis, amid continued violence in the capital, Dakar.
Opponents of President Abdoulaye Wade want him to step down instead of run for a third term in the forthcoming weekend's election.
Obasanjo met Idrissa Seck, a former prime minister and one of the leading opposition candidates, on Wednesday at a hotel in Dakar in what was the first of several such planned meetings.
The African elder statesman is in Senegal as the head of a joint mission between the African Union and the Economic Community of West African States (ECOWAS).
After his meeting with Obasanjo, Seck said the opposition remained steadfast in their effort to get Wade to stop his candidacy.
He said his supporters would be demonstrating later in the day in a "peaceful" fashion, but that they would wait for Obasanjo to meet all parties before taking a decision on the way forward.
Opposition leaders have given warning that they would make Senegal ungovernable if the 85-year-old Wade - Africa's second oldest head of state - contested the election.
Obasanjo said on Tuesday that his message was "this country is very beautiful, and nothing should be done to destroy it."
An ECOWAS statement said Obasanjo's mission was "to engage all the political stakeholders in Senegal with a view to promoting dialogue and ensuring peaceful, fair and transparent elections."
Wade's camp said Obasanjo was welcome to observe the election but made it clear there was nothing to mediate.
|Music star and political activist Youssou Ndour attended an opposition protest in Dakar on Tuesday [Reuters]
In another poll-related development, the entourage of Youssou Ndour, the music icon and opposition activist, said he was injured in the leg after being hit by a projectile at the scene of a banned rally in Dakar.
Ndour's candidacy was rejected by the constitutional court.
"Youssou Ndour was injured in the left leg, he has been seen by a doctor, but he doesn't want to make a big issue out of it and we won't be giving any more comment," Charles Faye, spokesman for Ndour's Fekke ma ci boole [I am involved] movement, said.
Separately, witnesses said police fired tear gas and opposition demonstrators hurled stones in central Dakar.
A few hundred metres away from Independence Square, policemen were locked in a confrontation with a group of protesters headed by Seck and Ndour.
"Dictatorship is going [on] in Senegal," Seck said, "because all the rights that are protected by the constitution and the laws of this country are being thrown out by this candidate."
Ndour said: "This situation is the situation Mr Wade created in Senegal. He doesn't have the right to be a candidate in this election."
'Get out, old man'
Hundreds of supporters gathered around the two opposition leaders' vehicles, chanting in the Wolof language, "Get out, old man", in reference to Wade.
"By no means did this standoff with riot police relate to some of the worst aspects of violence in Senegal - particularly Dakar's suburbs - this past month," Al Jazeera's Andrew Simmons said.
"But it shows the determination of leading opposition figures and protest movements to converge on a symbolic focal point: Independence Square. There is every indication that the situation will escalate."
Wade's opponents say his candidacy is illegal because it breaches rules setting a two-term limit, and accuse him of backtracking on his own statements that he would not stand for re-election.
Wade has argued that he is eligible to stand as the limits were added to the constitution after he had started his first term in 2000.