Senegal's ruling party has abandoned efforts to change the constitution after riots by opposition supporters in the capital, Dakar.

The protesters clashed with riot police on Thursday and demanded the constitution remain unchanged.

Opposition supporters said a proposed amendment would make it easier for President Abdoulaye Wade to stay in power.

The current constitution says a president must be elected with an absolute majority of the vote — 50 percent plus 1. The ruling party had sought to lower that threshold to 25 percent.

The proposed amendment would also have created a new post of vice president, which opponents believe was intended for Mr. Wade's son.

Justice Minister Cheikh Tidiane told lawmakers on Thursday the election clause of the constitution will stay the same.

Earlier Thursday, riot police used tear gas and water cannon against stone-throwing demonstrators at the main square in front of the National Assembly building during an hour-long battle.

Clashes also spread to the nearby National Cathedral, where opposition protesters fought with pro-Wade demonstrators.

The United States and France had both expressed concern about the ruling party's proposed constitutional amendments.