BAGHDAD, Iraq – An al-Qaida-linked group said Monday it was holding captive two U.S. privates, one from Texas and the other from Oregon, and taunted the U.S. military for failing to find the soldiers despite a search involving more than 8,000 Iraqi and American troops.

The Mujahedeen Shura Council, an umbrella organization for a variety of insurgent factions led by al-Qaida in Iraq, offered no video, identification cards or other evidence to prove that they have the Americans. The group had vowed to seek revenge for the June 7 killing of Abu Musab al-Zarqawi, the leader of al-Qaida in Iraq, in a U.S. airstrike.

The council also said it was responsible for the June 3 kidnapping of four Russian Embassy workers.

The two separate postings could not be authenticated, but they appeared on a Web site known for publishing messages from insurgent groups in Iraq.

Pentagon spokesman Bryan Whitman, when asked about the claim by the Shura Council that it was holding the soldiers, said, “We have no independent confirmation of that report.”

Besides the troops, the U.S. military said Monday it has deployed fighter jets, helicopters, unmanned drones, boats and dive teams in the hunt for the soldiers, who disappeared Friday in a region south of Baghdad known as the “Triangle of Death.”

Troops searching for the soldiers killed three suspected insurgents and detained 34 in fighting that also left seven U.S. servicemen wounded, said military spokesman Maj. Gen. William Caldwell.

The area is among the most dangerous in Iraq for U.S. troops and mostly populated by minority Sunni Arabs, the backbone of Iraq’s 3-year-old insurgency. The two soldiers were missing after an attack on their traffic checkpoint that left one of their comrades dead.

Ahmed Khalaf Falah told The Associated Press that he witnessed seven masked gunmen seize the soldiers near Youssifiyah, about 12 miles south of Baghdad.

Iraqi Foreign Minister Hoshyar Zebari said Sunday that insurgents had taken the soldiers prisoner. “Hopefully they would be found and released as soon as possible,” he said on CNN’s “Late Edition.”

Secretary of State Condoleezza Rice said there was “great concern” over the missing soldiers.

“The American military has made very clear that they are going to do everything possible … to try and find them,” she told reporters.

Kidnappings of U.S. service members have been rare since the 2003 U.S.-led invasion, despite the presence of about 130,000 forces.

U.S. troops patrol only in convoys. Foot patrols, while common in parts of Iraq during 2003 and 2004, have become rare because of roadside bombs, snipers and ambushes.