Lt. Gen. Goetz Gliemeroth, commander of the 5,000-strong NATO-led International Security Assistance Force in Kabul, said on Tuesday that according to intelligence reports, the new militants come from Saudi Arabia, Yemen or the Russian republic of Chechnya.
He said many already have been caught or killed in operations along the rugged, mountainous border region between Pakistan and Afghanistan, where Osama bin Laden and other al Qaeda operatives are believed to be hiding.
"Apart from, if I may say so, the typical terrorist, we've got a new species," Gliemeroth said at a regular briefing. They are "excellently trained and…they also have improved technique at hand."
In the wake of the Sept. 11, 2001 terrorist attacks, the United States invaded Afghanistan and drove the Taliban from power.
But many of the group's leaders and foot soldiers are believed to have escaped to the region near the Pakistan border.
Defense Secretary Donald H. Rumsfeld said in a memo published Wednesday that the war in Afghanistan, like the fight in Iraq, will be won after a "long, hard slog." He said the military had enjoyed more success hunting down members of Saddam Hussein's regime than it had tracking Taliban leaders.
In recent weeks, Taliban rebels have stepped up attacks against government troops, aid workers and U.S.-led coalition forces..
Three bombs exploded in Afghanistan's eastern city of Jalalabad Wednesday, tearing down walls at two government offices, police said. Taliban spokesman Maulvi Abdur Rahman Mansoor claimed responsibility for the attacks, saying "we will carry out more such operations against the oppressors."
On Monday, pamphlets purportedly signed by Mansoor were distributed in the northern Pakistani city of Peshawar, vowing the Taliban will continue their holy war against the Americans until they leave Afghanistan.
ISAF currently is confined to Kabul but the U.N. Security Council last week voted unanimously to allow the 31-country force to fan out to key cities in some of Afghanistan's most lawless provinces, where feuding warlords hold power.
Separately, an 11,500-member U.S.-led fighting coalition is in the country hunting down al Qaeda fugitives and remnants of Taliban insurgents.
Gliemeroth said it was unclear if the new terrorists were working in tandem with a particular group. He warned: "Against suicide bombs, there is no waterproof protection."
The traffic back and forth across the sparsely inhabited border region has been a source of contention between Pakistan and the Afghan government of President Hamid Karzai.
Karzai has accused the Pakistanis of sheltering fighters of the ousted Taliban regime and members of al Qaeda.
Pakistan denies knowingly giving safe haven to Afghan insurgents and says it is doing whatever possible to stop rebels from using its soil against Afghanistan's fledging government, including fortifying its long border with Afghanistan with fences and checkpoints.
New light towers and checkpoints were being erected along the barren western frontier around the town of Chaman, a main border crossing, about 470 miles southwest of the capital, Islamabad, to stop Afghan insurgents from reaching Pakistan, said Gen. Shaukat Sultan.
The Pakistan army recently launched large-scale raids on the ultraconservative Waziristan region to crackdown on Taliban and al Qaeda insurgents, while coalition forces operated on the Afghan side of the border to trap the insurgents.
Pakistan, a key ally of the United States in its war on terror, has arrested at least 450 al Qaeda suspects. They include at least two others allegedly involved in the Sept. 11 attacks, Khalid Shaikh Mohammed and Ramzi Binalshib.
A Yemeni national arrested this week during a routine security check at a roadblock in eastern Pakistan is believed to be an aide of captured al Qaeda financial manager Abu Zubaydah, a police official said on Wednesday.
Zubaydah is believed to have been one of the key money handlers in al Qaeda and an organizer of the Sept. 11, 2001, attacks in the United States.
Meanwhile, the Afghan government denied Wednesday that it has entered into talks with former Taliban members, including the ex-foreign minister who is being held by the U.S.-led anti-terror coalition.
Karzai's office has received a "number of individual contacts" from some ex-Taliban, including former Foreign Minister Abdul Wakil Mutawakil, "expressing interest and readiness to side with the government and offering assistance."
But the president's office said in a statement that it hasn't responded to them.