The violent attacks in Iraq have been largely blamed on terrorists linked to al-Qaida. Among them is Ansar al-Islam, a shadowy group with roots in the northern Kurdish regions of Iraq. U.S officials believe Ansar al-Islam's attacks have killed hundreds since the U.S.-led invasion two years ago.

The attacks have been bold and violent. This is the "war-on-terrorism's" frontline and it is taking a heavy toll on coalition forces and Iraqi civilians alike.

Many of the most violent attacks have been blamed on the terrorist group Ansar al-Islam. It was formed less than four years ago in the Kurdish regions of northern Iraq by the merger of two existing radical groups.

"Both of these groups -- Jund al-Islam and the Islamic Revolution of Kurdistan group --were groups that had been established with two particular objectives: Kurdish nationalism and extreme fundamentalist Islam," said Ambassador David Mack, a terrorism expert at the Middle East Institute in Washington.

He said that since the ouster of Saddam Hussein, Ansar al-Islam has expanded its goals to destabilizing the fledging Iraqi democracy and undermining the new government's international support. This tactic has led to devastating attacks on UN headquarters and the Jordanian Embassy  in Baghdad. 

And it has ties to al-Qaida through Abu Masab al-Zarqawi, a Sunni Muslim and head of al-Qaida in Iraq. Matt Levitt of the Washington Institute for near East Policy says the ties are growing.

"I think Ansar al-Islam has some pretty strong connections to the al-Qaida core. They certainly have relationships with Zarqawi. There's debate as to whether or not Zarqawi was the head of Ansar  al-Islam, [or whether] he's connected to Ansar al-Islam.  The nature of the relationships [is] unclear. What's important is to understand and recognize that they are there," explains Matt Levitt.

The U.S. State Department has designated Ansar al-Islam a "Foreign Terrorist Organization" and says it is one of the leading groups engaged in anti-coalition attacks in Iraq.

Mr. Levitt believes Ansar al-Islam is also developing closer ties to radical groups in Europe. "But it's clear that today they are most proactive in recruiting European Muslims to go and fight in Iraq. And this has the Europeans very, very concerned."

Abdeslam Maghraoui, a Muslim specialist at the United States Institute of Peace, sees a "troubling trend" in this recruitment activity. "?That sometimes joining the jihad (has) become something really cool for youngsters. These are not serious, professional terrorists.  But the fact that joining the jihad has become something trendy is very disturbing."

In addition, many terrorism experts including David Mack fear as stability improves in Iraq, Ansar al-Islam will simply move its base of operation.

"And its also entirely probable that they will turn up in Europe where there are very large Kurdish communities, where they probably have some sympathizers, and where they might be in a position to engage in terrorist activity directly against European governments and against U.S. diplomatic establishments or U.S. companies," says Mr. Mack.

Preventing such attacks is difficult because terrorist groups like Ansar al-Islam are constantly adapting their strategies.

"That means they are not only revolutionary which is how we tend to think of terrorists, but evolutionary. Evolutionary in their tactics, evolutionary in their fund raising and logistical support activities," adds Mr. Levitt.

And that, says Matt Levitt, is what makes stopping terrorist organizations like Ansar al-Islam so problematic. Just as quickly as steps are taken to counter their tactics, they find new ways to accomplish their goals.