Riot police are stationed throughout much of Senegal's capital, Dakar, where more protests are expected against President Abdoulaye Wade's plan to run for a third term.

An opposition movement known as M23 called for peaceful demonstrations on Tuesday. The government authorized the demonstration just a short time before it was due to begin.

Witnesses describe the capital as very tense, with many people constantly monitoring news reports and largely staying away from the city's center, where the protests are expected to take place.

M23 leaders said they called for the protests to pressure the 85-year-old president to withdraw from the February 26 election.

Senegal's constitutional court ruled Friday that the incumbent can run for a third term, even though the constitution limits presidents to two terms. President Wade argued the rule did not apply to him because it became law after he was elected.

The ruling sparked riots in Dakar and other cities that have killed at least three people.

It has also raised international expressions of concern and pleas for calm.

Mr. Wade was first elected president in 2000, and re-elected in 2007.

In June, anti-government riots broke out in Dakar after the ruling party moved to create the post of vice president and lower the percentage of votes needed to win the presidential election.

The president's opponents said the moves were aimed at making it easier for Mr. Wade to be re-elected, and for his son, Karim Wade, to succeed him. The proposals were later dropped.