There are signs that more foreign fighters are joining the Taliban in Afghanistan. These foreign militants are believed responsible for the upsurge in suicide bombings -- and some experts say they have strengthened the Taliban insurgency. More from VOA's Bill Rodgers.

The Taliban always had foreigners in its ranks, but experts say a new surge is bolstering the insurgency.

Most are Pakistani militants, who slip across the border into Afghanistan to join the Taliban. But there are other nationalities as well -- says Seth Jones, a specialist on Afghanistan at the Rand Corporation. "Small numbers are Arabs, especially Saudis, Libyans, Egyptians. A small number also of Uzbeks, Chechens and some other Central Asians. But the bulk of these are Pakistanis, including Pakistani Pashtuns."

A suspected fighter from Siberia was featured in a recent New York Times article -- his capture an indication of how foreigners are coming to the region to fight alongside the Taliban.

As in the 1980s when foreigners came to Afghanistan to fight against occupying Soviet forces, the motivation for this new generation of foreign militants is holy war.

Jones adds, "Like Iraq in many ways, this is a fight against what these individuals consider to be a major jihad against an unwelcome western foreign presence in Afghanistan. These are crusaders who are trying to destroy Islam, in their view, so this is about fighting a jihad against an unwelcome visitor."

NATO forces fighting the insurgency, are picking up evidence of these foreign militants. But the U.S. military says there is no sign of a foreign fighter surge.

U.S. Brigadier General Rodney Anderson recently said, "We have, through communications monitoring, we have heard dialects that appear to be coming from outside the region. We have not gotten any specific information that would lead us to believe there is a large influx, or significant influx, of foreign fighters."

But the number of suicide attacks is at a record high -- and most are believed to be carried out by foreign militants.

The impact and casualties caused by these attacks outweigh the relatively small number of foreign fighters believed to be in Afghanistan.

Again, Jones explains. "The Arabs, the Russians, the Chechens, the Central Asians that have been involved in the fighting, they bring, what I call, a force multiplier capability to the insurgency. And that is, they provide increased ability to kill Afghan and NATO forces through suicide attacks. There are much more sophisticated improvised explosive device attacks, use of the Internet and other media activities. These foreigners increase the ability of local Taliban to fight and then conduct an information campaign."

And because of that, the Taliban insurgency is a more effective fighting force -- according to Afghan expert Alam Payind. "I don't think that the Afghani Taliban are capable of sustaining this kind of surge as they are doing right now without the backing of al-Qaida and this foreign insurgent group. So without them, I don't think the Taliban are sustainable."

Despite Taliban video releases, the U.S. military says the insurgency is limited, able only to stage hit-and-run attacks -- and not hold territory.

Yet the impact on civilians of the deadly suicide bombings, experts say, works to undermine support for the Afghan government.