Amnesty International released satellite images yesterday revealing that large areas of Nigerian towns have been razed to the ground in assaults by Boko Haram.

The human rights charity said photos of Baga and Doron Baga showed that more than 3,700 structures had been damaged or completely destroyed.

Extremist Islamist outfit Boko Haram stormed a military base in Baga on January 3 and then went on the rampage for days, shooting hundreds of civilians.

Last week Amnesty said some reports suggested as many as 2,000 people had been killed.

Villagers in threatened areas of northern Nigeria, where Boko Haram is strongest, have been fleeing to cities in their own country and in Chad, Niger and Cameroon.

Denmark announced an extra 12.5 million kroner (£1.3m) yesterday to help victims of the terrorist organisation, saying the money would be channelled through the Red Cross and the United Nations.