Fresh clashes erupted in Senegal Wednesday as the opposition mulled a new strategy to force octogenarian leader Abdoulaye Wade to scrap his controversial ambitions for a third term in office.

Pressure mounted on Wade with former colonial ruler France demanding a "generational change" and UN Secretary General Ban Ki-moon expressing concern as police on Wednesday used tear gas and rubber bullets on student protestors.

The June 23 Movement (M23) opposition movement on Tuesday night gathered some 10,000 protesters, according to witnesses, to rally against the 85-year-old leader's bid to seek a third term in the February 26 polls.

The rally degenerated into riots as police tried to disperse the crowd with tear gas, and a 32-year-old student was killed when a police car ploughed into a group of protesters, witnesses said. Police deny it was their vehicle.

The student's death was the fourth casualty in a week.

At the University of Dakar, students angry over the death clashed Wednesday with police who fired tear gas and rubber bullets after being pelted with stones, an AFP journalist reported.

Senegal's top court on Monday dismissed all final appeals against Wade's candidacy, leaving no recourse for the opposition but street pressure.

While thousands turned out to demand Wade step aside, presidential spokesman Serigne Mbacke Ndiaye said the protest as a failure and proved that Wade commanded wide support.

"If 13 candidates supported by nearly 70 political parties and civil society organisations only managed to mobilise 2,500 people, it proves Abdoulaye Wade holds a majority in Senegal," he said in a statement.

However M23 spokesman Abdoul Aziz Diop denied the claim.

"Our capacity for mobilisation has not been contradicted, the movement achieved maximum mobilisation."

Diop said a "crisis committee will meet today to evaluate the next step after the protest. But from now on we will take into account the repression by the government and develop a strategy against it."

Wade critics accuse him of fiddling with the law to remain in power.

Wade says a constitutional amendment to presidential terms does not apply retroactively, which means the two terms he has already served cannot be taken into account and theoretically allows him to serve two more seven-year terms from 2012.

A policeman was killed in riots last Friday when the council gave Wade the green light, and two people were shot dead by police during protests on Sunday in the northern city of Podor.

French Foreign Minister Alain Juppe said the country "wished a generational change could be organised," in the first sign the former colonial master would prefer Wade step down.

This echoed earlier calls from Washington which urged Wade, in office since 2000, to allow power to pass "to the next generation."

Amnesty International urged the government to rein in its security forces.

"Police may be faced with hostile demonstrators but the security forces must do everything in their power to preserve life -- not threaten it," west African researcher Salvatore Sagues said in a statement.

Senegal's Foreign Minister Madicke Niang told journalists that while Senegal was open to advice, it would not "take lessons in democracy from anyone."

"The election will not take place neither in the United States, nor France, nor anywhere else," he said.

The opposition has vowed to bar Wade from running and has called for popular resistance against what they term a "constitutional coup d'etat."