Thousands fled fighting in Congo's capital Brazzaville as the government blamed hours of heavy clashes in opposition bastions on a rebel group known as "The Ninjas".
There was no official toll from what the government called "a terrorist action", as it said it was investigating whether the assailants were linked to opposition leaders contesting President Denis Sassou Nguesso's re-election last month.
Late yesterday, Congo's constitutional court confirmed the March 20 election victory of the former paratrooper colonel, who has ruled the country for more than 32 years despite accusations from critics of rampant corruption and nepotism.
The results of the poll, in which Sassou Nguesso took more than 60 percent of the vote, had been denounced by the five defeated candidates who allege "massive fraud".
Streams of people panicked by gunfire fled districts loyal to the opposition in the south of Brazzaville, carrying their bags and pushing the elderly in wheelbarrows.
In a televised statement early afternoon, government spokesman Thierry Moungalla said the situation was "under control" and called on people to "remain calm and return to their usual business."
He blamed the fighting on "disbanded Ninja Nsiloulou" fighters, saying they had attacked an army position as well as four police stations.
The rebel group from a late 1990s conflict was headed by Protestant preacher Frederic Bintsamou, known as Pastor Ntumi, whose trademark colour is purple and who disbanded the group in return for a junior government position.
He recently came out in favour of presidential candidate Guy-Brice Parfait Kolelas, who ran second to Sassou Nguesso in last month's vote.
The constitutional court yesterday ruled that Kolelas' request to have the results of four regions annulled was "inadmissable as it was filed after the constitutional deadlines".
"We live in a country where, whether you vote or not, peace is always under threat," said a woman in the city's restive south who gave her name as Julienne.
According to several witnesses, the crackle of automatic gunfire began after 2:00 am (0100 GMT) in the southern Makelekele and Mayana districts, and continued without stop until dawn. Intermittent shooting continued into the afternoon.
