The Taliban declared the start of a spring offensive across Afghanistan on Saturday, against foreign troops in Afghanistan as well as Afghan security forces and government officials, just after high-ranking US military officers predicted such a move from the group.

In a statement, Taliban warned Afghan civilians to stay away from public gatherings, military bases and convoys, as well as Afghan government centres and buildings, as these would be the focus of attacks starting on May 1.

"The Leadership Council of the Islamic Emirate of Afghanistan wants to declare the launching of the spring military operations named as "Badar" to be waged against the invading Americans and their foreign allies and internal supports," the Taliban said in an emailed statement.

"Operations will focus on attacks against military centres, places of gatherings, airbases, ammunition and logistical military convoys of the foreign invaders in all parts of the country," the Taliban said.

Senior military officials told Reuters on Friday that recent intelligence reporting indicated the campaign of increased violence would last about a week and would be mounted by the Taliban, supported by the al Qaeda-linked Haqqani network and other insurgents.

A Pentagon report, released on Friday, painted a more positive picture of the situation on the ground saying that the US-led coalition has made "tangible progress".

Last week eight US soldiers and a contractorwere killed after an Afghan army officer opened fired at the air force headquarters in Kabul airport.

The Taliban said the targets of the attacks would be foreign forces, high-ranking officials of President Hamid Karzai's government, members of the cabinet and lawmakers, as well as the heads of foreign and local companies working for the NATO-led coalition.

"All Afghan people should bear in mind to keep away from gatherings, convoys and centres of the enemy so that they will not become harmed during attacks of Mujahideen against the enemy," the Taliban said.

In the statement, the Taliban also said that fighting in Afghanistan would not end until foreign troops had left the country. They also called on Afghan government officials and security forces to switch sides to the fighters.

Agencies