Afghan Taliban chief vows "unimaginable" violence

KANDAHAR, Afghanistan, Mar 16 (Reuters) Taliban leader Mullah Mohammad Omar vowed a ferocious offensive against US-led forces in Afghanistan, saying they would soon face unimaginable violence.

An insurgency that has killed more than 1,500 people since the start of last year has intensified in recent months with a wave of suicide bombings, including at least 12 this year.

Ten US troops have been killed in combat this year and US commanders have said they expect violence to increase in coming months as the weather warms, snow on mountain passes melts, and Afghanistan's traditional fighting season begins.

''With the arrival of the warm weather, we will make the ground so hot for the invaders it will be unimaginable for them,'' Omar said in his message, read by Taliban spokesman Mohammad Hanif over the telephone from an undisclosed location.

The fugitive Taliban leader, who carries a 10 million dollars reward, also said a stream of young Afghans were volunteering for suicide missions, the Pakistan-based Afghan Islamic Press news agency said.

Last week, Afghan President Hamid Karzai called for more Pakistani cooperation in fighting militants after Islamabad derided Kabul's accusations that Mullah Omar was in Pakistan.

Afghanistan's Foreign Minister Abdullah Abdullah yesterday said he was sure the Taliban leader was not in Afghanistan, although Taliban spokesmen insist Omar is leading the insurgency from his homeland.

''Mullah Omar is not in Afghanistan, that's as much as I can say with a degree of certainty,'' Abdullah told Reuters during a visit to the Malaysian capital of Kuala Lumpur.

Afghan officials complain that the Taliban use Pakistan's tribal regions as a springboard for attacks, and despite Islamabad's denials, many suspect Pakistan harbours long term ambitions to have a pro-Pakistan government in Kabul.

TO GET WORSE BEFORE IT GETS BETTER A US commander said last week an upsurge in violence was expected as US and NATO forces extend their reach into parts of Afghanistan where the insurgent presence is greater.

''We anticipate that we are going to see a fairly violent spring and summer and then an improvement in overall conditions,'' US Navy Rear Admiral Robert Moeller, US Central Command director for plans and policy, told a congressional hearing.

The 26-member NATO alliance is preparing to expand its International Security Assistance Force mission -- already in the north, west and in the capital Kabul -- to the more volatile south and ultimately the east, raising its troop numbers to 16,000 from 9,000.

About 18,000 US troops in the country are targeting Taliban and al Qaeda forces, but the United States hope to cut numbers by several thousand as NATO forces take on more responsibilities and the Afghan army becomes stronger.

Pakistan has deployed around 80,000 soldiers in frontier areas to try to stop militants moving across the border, and it coordinates with US and Afghan forces on the other side.

The Taliban took power in Kabul in the mid-1990s with Pakistan's backing. Under US pressure, Pakistan abandoned support for the Taliban in late 2001, after its leaders refused to surrender al Qaeda chief Osama bin Laden following the Sept. 11 attacks on New York and Washington.

REUTERS DKS RK1420