Up to 12 people are reported to have died in fighting in Madagascar's north-eastern, vanilla-producing region of Diego Suarez.

Seven soldiers and three civilians were killed on Monday, reports the French news agency, AFP, quoting hospital and military sources.

Veteran leader Didier Ratsiraka dispatched elite troops to recapture the regional capital of Sambava on Monday after it was taken by troops loyal to new President Marc Ravalomanana.

The BBC's Alastair Leithead says this is the largest military clash since political turmoil followed disputed elections last December.

He says that around 300 troops on each side are involved.

According to AFP, a truce was declared overnight and the situation was calm on Tuesday morning.

Surprise attack

Vanilla is the main cash crop of the island nation, whose economy has been devastated by blockades imposed on the capital, Antananarivo, by supporters of Mr Ratsiraka, based in the eastern port city of Tamatave.

Ravalomanana's supporters have vowed to break the blockade

This fighting follows repeated warnings by Mr Ravalomanana's officials that they would use force to break the blockades on their Antananarivo stronghold.

However, Sambava does not have a major port and analysts are surprised that it has been attacked.

Mr Ravalomanana told the BBC that the attack was in response to reports of human rights abuses in the area by supporters of Mr Ratsiraka.

Fuel and food are becoming scarce in Antananarivo and aid workers warn of a "creeping" humanitarian emergency.

The BBC's Jonny Donovan in Madagascar says that Mr Ravalomanana is under pressure from Antananarivo residents to end the blockades.

Phones cut

Mr Ravalomanana was sworn in as president last month but Mr Ratsiraka has refused to recognise his defeat.

The French-trained commandos, the Rapid Intervention Force (RFI), have remained loyal to Mr Ratsiraka throughout the dispute and were on Monday sent to retake Sambava and the surrounding region of Diego Suarez.

Ratsiraka is refusing to stand down

Our correspondent says that details of the fighting are difficult to come by as the phones lines are being cut.

Last week, an attempt to take control of the airport in the country's second port city of Mahajanga by Mr Ravalomanana's forces was repulsed.

The fighting shows that Mr Ravalomanana and his backers and now trying to solve the long-running dispute by military action and not negotiation, our correspondent says.