Voice of America reported protesters threw rocks, and police fired tear gas and hot water cannons police into the crowd that gathered in Dakar's central squares to urge 85-year-old President Abdoulaye Wade to drop out of the Feb. 26 election.
Senegalese singer and opposition candidate Youssou N'Dour implored the crowd to remain peaceful, telling the demonstrators Senegal is "our nation" and not to ruin it, VOA said.
Cheikh Alasane, an academic who was among the protesters who were angered by a court ruling last Friday that allowed Wade to pursue another term, said "the time has come for each of us to confront ourselves these problems that have been given to us."
"This is a flagrant violation of the Constitution," he said. "When someone wants to tear this apart, people are obliged to take their courage in their hands and fight this regime which wants to put us on our knees."
Amnesty International said in a release that two people were killed during protests in Podor. The rights group said a young male protester and an elderly female bystander were shot dead by police.
"Today's bloodshed marks a dramatic escalation in the violence that has plagued Senegal in the run up to its elections," said Salvatore Sagues, Amnesty International's West Africa researcher. "As further protests are planned for tomorrow, we call on the authorities to refrain from using live bullets against peaceful protesters."