Malian soldiers on Monday evacuated the main market in Gao over fears of an attack, after the northern city was shaken by three days of suicide bombings and guerrilla gun battles claimed by Islamists.

"We fear an attack, that is why we are evacuating the Gao market for security reasons," said a high-ranking officer.

France bombed Islamist targets in northern Mali on Monday following a string of guerrilla attacks by the extremists a month after Paris launched an offensive to drive them from its former colony.

In a pre-dawn attack, witnesses said a French army helicopter destroyed a central police station in the northern city of Gao from where rebels from the Movement for Oneness and Jihad in West Africa (MUJAO) had opened fire from the station on Malian troops Sunday, sparking an hours-long street battle.

Northern Mali's largest city was rocked by its second suicide bombing in two days, a soldier said Sunday, as Islamist rebels continued defying a security lock-down on territory reclaimed by French-led forces.

The twin suicide blasts, the first such attacks in Mali, underlined the threat of a drawn-out insurgency as France, whose warplanes were still bombing northern territory Sunday morning, tries to map an exit strategy nearly one month into its intervention in its former colony.

Malian troops bolstered security at army checkpoints and villagers detained two youths allegedly strapped with explosives on Saturday after Islamists claimed responsibility for the country's first suicide attack.

Residents of a village near Gao, the largest city in the north, detained two youths they said were wearing explosive-rigged belts and traveling on the same road where the suicide bombing on Friday wounded a soldier at a checkpoint.

French-led troops Saturday seized the airport and a key bridge serving the Islamist stronghold of Gao in a major boost to a 16-day-old offensive to rout Al-Qaida-linked rebels from Mali's sprawling desert north.

The stunning advance came as the extremist Muslim group controlling Gao since June said it was ready for talks to free a 61-year-old French hostage kidnapped in November.

French warplanes destroyed two Islamist bases in northern Mali as a leading al-Qaida-linked group in the region split Thursday, with the breakaway group saying it wanted talks to end a Paris-led offensive against the militants.

The French bombing raids overnight targeted Ansongo, about 80 kilometers (50 miles) from the town of Gao and extremist bases in the nearby village of the Seyna Sonrai, a Malian military source said on condition of anonymity.

Residents of the Islamist-held northern Mali town of Gao on Saturday killed a local jihadist leader to avenge the murder of a journalist, an official said.

Sema Maiga, a deputy of the town's mayor, said the Islamists beat local journalist Kader Toure to death after accusing him of "working for the enemy", adding that residents then "killed an Islamist chief called Alioune Toure".

Residents of Gao in Islamist-occupied northern Mali on Sunday prevented extremists from chopping off the hand of a thief, the penalty for stealing according to strict sharia law, residents told Agence France Presse.

"They (Islamists) were not able to cut off the thief's hand. Very early on Sunday hundreds of youths stormed independence square in Gao to prevent the sentence being carried out," a local teacher told AFP by telephone.

Tuareg rebels claimed control of the legendary desert town of Timbuktu on Sunday, part of a dramatic push across northern Mali, as the disorganized junta indicated it was ready to cede power.

Tuareg rebels assisted by Islamist fighters have swept across much of northern Mali since renegade soldiers staged a coup on March 22, saying they were fed up with the government's handling of a Tuareg fight for an independent homeland.