Senegal's President Abdoulaye Wade issued a call for calm Friday as he pursued his controversial campaign for a third term in the face of sometimes violent protests.

"We are launching an appeal for calm to everyone," his spokesman Serigne Mbacke Ndiaye told reporters.

"There's no point shooting each other, insulting each other, that doesn't achieve anything," he added.

"We are not enemies," said the spokesman, referring to the political leaders in the race for the presidency. It serves no purpose to launch attacks on each other's homes or on political meetings, he added.

"I deplore and condemn" all act of political violence, said the spokesman, saying he was "almost certain that no leader had called on his supporters to attack anyone." But leaders could not control everyone, he noted.

The electoral campaign, which got underway on Sunday and is due to end on the 24, two days before the first round of the election, has been marred by violence.

Protests since January 27, when the country's highest court cleared Wade to run for a third term, have left four people dead in the last five days.

Eight opposition candidates, including the famous singer Youssou Ndour whose candidacy was rejected by the court, have joined forces in a campaign to get the 85-year-old president to withdraw his candidacy.

He will face 13 other candidates in an open race with no clear opposition favourite, and a split vote that could hurt their bid to oust Wade from office.

Wade introduced two-term limits into the country's constitution for the first time to strengthen its democracy.

But in 2008 he extended the length of those mandates and now says that entitles him to two seven-year terms from 2012.

The opposition has vowed to pressure him to withdraw his candidacy and Washington and Paris have both criticised his re-election bid.