Libreville - Gabon's failed presidential candidate Jean Ping called for a general strike after days of violence following incumbent Ali Bongo's disputed re-election, saying an economic blockage would "topple the tyrant."But the centre of the capital Libreville was its usual bustling self, despite Ping's appeal for a massive work stoppage.After being shuttered for days over the post-election violence, banks and shops were re-opened in the seaside city and taxis were returning to the streets. Many shops however offered only limited provisions as the unrest had stalled deliveries.Post-election chaos has claimed at least seven lives in the oil-rich central African nation, ruled by the Bongo family since 1967.Bongo's rival Ping, a veteran diplomat who has held a top African Union job and served as foreign minister, has already vowed to challenge the result."We cannot accept that our people will be killed like animals without reacting," Ping said on Facebook. "I propose to cease all activity and begin a general strike."We must use all means of resistance to topple this tyrant and believe me, he is on the verge of falling," Ping added.Bongo was declared victorious by a razor-thin margin of just under 6 000 votes, but Ping has insisted the vote was rigged and claimed victory for himself. He is calling for a recount -- something the Gabonese authorities have so far refused to do.The internet was accessible after a five-day blackout but social media networks remained blocked. Meanwhile, speculation mounts that Ping could launch an appeal at the Constitutional Court for a recount. However many of his supporters feel this is not a viable option as they question the courts impartiality.They say fraud is rampant, notably in the Bongo fiefdom of Haut-Ogooue in the east. It is one of the country's nine provinces and turnout there, according to official figures, crossed 99% with 95% voting for the president.- International concern -The violence after the announcement of the results has sparked international concern with top diplomats calling for restraint as rights groups raised alarm over the use of excessive force.At least seven people have died and some 800 people have been arrested in the capital UN chief Ban Ki-moon has spoken to both Bongo and Ping and has "deplored the loss of life", a UN statement said."He expressed concern about the continuing inflammatory messages being disseminated and called for an immediate end to all acts of violence in the country," it said.Tensions remained high in the economic capital Port-Gentil and Total workers turned up for the first since Tuesday, a management source in the French oil giant said.A Total worker said there had been gunshots heard in the city overnight. "The refinery remains closed. The teams working round-the-clock are only there to ensure security," said an official at Sogara, Gabon's sole refinery jointly owned by the government and a clutch of major international firms.The troubles have also caused prices to rocket. "Four chillies now cost 1,000 CFA francs (1.5 euros, $1.6) against 200 to 300 CFA francs earlier," said Andre, a resident from Lalala-a-gauche, a working class area in Libreville."Things will really start heating up," he said, echoing a widespread fear in the capital."This is the lull before the storm," said a fruit and vegetable wholesaler, speaking the central town of Lambarene.The country had previously enjoyed relative political stability, mainly because former colonial power France helped Omar Bongo rule for 41 years.After he died in June 2009, his son Ali won an election but opposition media claimed he had essentially been installed by France.