Demonstrators set ablaze Gabon’s National Assembly building on Wednesday afternoon and several civilians were killed as supporters of opposition leader Jean Ping clashed with security forces in the streets of Libreville, hours after President Ali Bongo’s disputed re-election was confirmed by the nation’s electoral body.

Police and soldiers had been stationed along most roads and petrol stations in the capital in anticipation of the violence as tension mounted, days after Ping declared himself winner before CENAP gave the official tally, Eyewitness News reported.

Earlier on Wednesday, Ping took to social media to declare that the Republican Guard had launched aerial and ground attacks on his party’s offices in the capital.

The elite force provides security for the president.

“Mon quartier general de campagne est pris a l’assaut a l’instant par la garde republicaine#Gabon (My election campaign headquarters are under attack from the Republican Guard),” read the statement on his Twitter page.

The government however denounced the claims saying that it was pursuing the criminals who had gathered at Ping’s party headquarters.

The government also shut down social media in the capital in the wake of the violence

The results by the Autonomous and Permanent National Electoral Commission (CENAP) gave the incumbent Bongo a slim margin victory of 5,594 votes over Ping. The number of registered voters was 627,805.

The election was rocked by allegations of lack of transparency after CENAP failed to release a list of the valid polling stations and registered voters.

Ping, US and the European Union (EU) called on the elections results from all polling stations to be made public.

The international community, led by EU Electoral monitoring team and US had earlier lamented irregularities in the process, adding that only half of the valid voters had received their ballot cards a week before the election on Saturday.

“The mission condemns the lack of transparency in the electoral bodies which failed to make essential information available to the campaigns, like the electoral roll or a list of polling stations,” Mariya Gabriel, a member of the EU team told Agence France Presse on Monday.

Ping and Bongo were once close allies and worked under, Bongo’s late father’s government before his death in 2009.

Ping, a career diplomat had also married Pascaline Ondimba, Omar Bongo’s eldest daughter and bore two children but later divorced her in early 90s.

He is a former chairman of the African Union Commission (AUC), in which he served from February 2008 to October 2012.

In 2009, similar clashes greeted Ali Bongo’s election to succeed his father. Several people were killed and the French Consulate in Port Gentil set ablaze.