LIBREVILLE, Gabon (AP) — Gabon's president has narrowly won re-election, election officials said Wednesday, keeping alive a family dynasty in this oil-rich Central African country that reaches back to the 1960s. Clashes quickly broke out in the capital as opposition supporters claimed election fraud.

President Ali Bongo Ondimba beat leading opposition candidate Jean Ping by just 1.57 percentage points, setting the stage for an almost certain challenge to the results.

Police fired tear gas at hundreds of opposition activists who converged near the Constitutional Court in the capital, Libreville. Witnesses said demonstrators in several districts vandalized a mall, looted a bank and burned buildings as army helicopters flew overhead.

Looting and clashes also followed Bongo's win in 2009, when he came to power after the death of his father, longtime ruler Omar Bongo.

Bongo won this election with 49.8 percent of the vote, while Ping had 48.23 percent. The constitutional court must finalize the electoral commission's provisional results.

The results came a day later than expected, prompting fears of a tainted process.

European Union observers criticized a "lack of transparency," and the EU called for the electoral commission to publish the results from all polling stations.

France and the United States also called for individual polling station results to be published. The U.S. Embassy said voters were not "well-served by the many systemic flaws and irregularities that we witnessed," including the late opening of polling stations and "last-minute changes to voting procedures."

The U.S. State Department urged calm and encouraged security forces to "act with both restraint and respect for the human rights of all Gabonese citizens."

Bongo, in a statement after his victory, congratulated everyone for voting in peace and transparency. "We are living in a moment where we must be more solid and more strong together," he said.