The U.S. military Thursday ended a three-week anti-terrorism exercise with African troops aimed at sharpening defenses against Al Qaeda-linked militants and denying them sanctuary in Africa's ungoverned spaces.

As many as 25 percent of the foreign fighters in Iraq went there from North Africa (search) to fight U.S. forces and their allies, and a small number of fighters are returning to North Africa, trained in guerrilla tactics and bomb-making, U.S. officials have said.

Starting June 6, 700 U.S. troops and 2,100 soldiers from nine North and West African nations conducted mock patrols, target practice and parachute drops in which hundreds of African soldiers leaped out of C-130 (search) transport planes.

Officers from the nine countries — Mali, Niger, Mauritania, Chad, Algeria, Tunisia, Morocco, Nigeria and Senegal — also met in Senegal (search) for an exercise aimed at increasing cooperation in case of a terrorist attack.

"Operation Flintlock" had achieved its goals, said Maj. Gen. Thomas Csrnko, the special forces commander for U.S. European Command, which oversees U.S. military activities in Europe and all of Africa, excluding the Horn.

"The exercise accomplished what we set out to do, which was to get cooperation from all the nations," Csrnko said. "This is hopefully the beginning of a long relationship between our forces and their commands."

The armies in the nine nations began receiving training from U.S. forces in 2003 with a $6 million budget that they want to boost to $100 million each year for five years starting in 2007.

"We want to help them create stable environment onto a dozen trucks earlier this month and attacked an isolated Mauritanian army outpost near the Algerian and Mali borders. The assault left 15 Mauritanian soldiers and nine Salafists dead.

The Salafists also are accused of kidnapping 32 European tourists in the Sahara in 2003 and of carrying out numerous attacks in Algeria itself.

"We understand the strategic importance of Africa," Csrnko said. "If you take away sanctuary, mobility and support from terrorist organizations like has been done in Afghanistan, they're gonna move somewhere else."