Authorities in Ivory Coast have deployed police reinforcements in Abidjan amid heightened political tensions surrounding a judge's decision Friday to grant opposition leader Alassane Ouattara a certificate of nationality.

Heavily armed police were deployed in greater numbers than usual in various districts of Ivory Coast's commercial capital and in some parts of the interior.

Alassane Ouattara, a former prime minister, has been at the center of a long political impasse that came to a head in the year 2000, when he was barred from running in presidential elections due to what the government said were doubts about whether he was of full Ivorian nationality.

Ouattara supporters who had called on the government to issue him a certificate of nationality were planning to hold a massive rally in Abidjan on July 9 to press their demand.

On Saturday, Mr. Ouattara and his attorneys announced that a judge had granted him the certificate on Friday. He and members of his Rally of the Republicans (RDR) party praised the judge's decision. Some Ivorians welcomed the news as a sign that a long-standing political crisis was finally ending.

The perception changed late Saturday, when supporters of President Laurent Gbagbo's Ivorian Popular Front (FPI) protested, saying the government should not have given in to Mr. Ouattara's followers' demands.

Gagbo supporters barricaded streets in some districts of Abidjan, but police promptly moved in to dismantle the barriers and disperse the protesters.

In an apparent effort to distance itself from the judge's decision, Interior Minister Emile Boga Doudou appeared on state television late Saturday saying the judge had acted independently and had not consulted with the Gbagbo administration in making her decision to issue citizenship papers to Mr. Ouattara.

A number of people have been killed in recent days in clashes between Ouattara and government supporters in the central Daloa region, as the country prepares for regional elections on July 7.

The clashes have been along both political and ethnic lines. Mr. Ouattara's supporters are members of the Muslim, northern Dioula ethnic group, while Mr. Gbagbo's supporters are of the central-western, mostly Christian Bete group.

The Daloa region remains under a dusk-to-dawn curfew.

Despite his having a certificate of nationality, analysts say, the government may still have legal grounds to bar Mr. Ouattara from running in the next presidential elections, scheduled for 2005.

The government has accused Mr. Ouattara of stating his nationality as Burkinabe on documents several years ago. An article in a constitution approved by referendum three years ago states that those who have identified themselves to be of another nationality are not eligible for the presidency.

RDR supporters on Sunday said they plan to go ahead with their scheduled march on July 9. Party members said they will now push for the removal of the article, which they believe was specifically written to exclude Mr. Ouattara from running for president.