Fans celebrate as they gather for Paris Saint-Germain players before they received the French Championship trophy at Trocadero square in front the Eiffel Tower in Paris, May 13, 2013. Fans later broke security barriers and clashed with police. [Photo/Agencies]

Small groups of riot police started to move forward, with the mood turning more menacing. Fans threw stones and other objects at the police, who replied by firing tear gas canisters.

"There were fireworks, flares and a bit of (tear) gas flying about," PSG defender Zoumana Camara said. "But you can understand that a bit because they (the fans) have been waiting for so long."

This was PSG's third league title and first since 1994. The violence comes three years after a PSG fan was killed in fighting outside Parc des Princes stadium - the second hooligan-related death at the club since 2006.

PSG had serious problems with hooliganism from 1985 to 2010. The club then took measures to combat the problem and radically changed its ticketing policy.

A fan gets injured during clashes between fans and police as several thousand supporters gathered to celebrate with Paris Saint-Germain soccer players who received the French Championship trophy in Paris, May 13, 2013. [Photo/Xinhua]

Former PSG player Ali Bernabia, who played for PSG from 1999-2001, questioned the location of the ceremony, saying it was an open invitation for fans to converge and making it difficult for police to control crowds.

"You can't expect everything to suddenly change and to host a trophy presentation at the Trocadero," Bernabia said on BFM television.

PSG also chose the Trocadero to present the signing of Zlatan Ibrahimovic last August, an event that brought some fighting among fans that day.

Sporting director Leonardo did not attend the ceremony after being hospitalized overnight, reportedly for a stress-related ailment. He was released Monday afternoon.

Leonardo argued with Ibrahimovic after Sunday's match, with television images showing the club's top scorer shouting at the sporting director in the changing room after the game.

The 1-0 win at Lyon on Sunday night clinched the championship for PSG with two rounds remaining.