According to a tally kept by the Associated Press, more than 150 educators have been killed, and thousands of others have fled the country. “I told the M.O.I. and M.O.D. if you can’t protect the universities, give me 800 recruits, and I will do this mission,” Mr. Ajili said, referring to the Ministry of Interior and Ministry of Defense. “But they rejected the idea.”

Shiite leaders have often said that kidnappers who have been linked to the interior ministry have in fact been criminal thugs, or even Sunni insurgents, who have acquired the military-style uniforms used in Tuesday’s attack, and many others, from street markets where they are widely available. Basil al-Khateed, a spokesman for the higher education ministry, noting that the employees taken captive were from different ethnic and religious groups, counseled against any hasty conclusions. “It’s not clear if this kidnapping was sectarian or not,” he said.

But the Shiite official who was among those released by the gunmen gave an account that appeared to leave little doubt that the abductors came from the area of eastern Baghdad that is heavily Shiite. He said the gunmen, having blindfolded their captives, yelled at motorists to clear the road as they headed east through the traffic from the ministry building, and crossed the Canal expressway. Beyond the expressway, in northeast Baghdad, lies Sadr City, the main stronghold of Shiiite militia groups, and to the south of it, near the bombed-out ruins of the United Nations building, one of the first targets of Sunni insurgent attacks in 2003, the district of Baladiyat. Wasteland between Baladiyat and Sadr City has sometimes been used to dump bodies of kidnap victims.

The official said the gunmen had taken their captives into a large hall with a concrete floor, then begun to quiz each of the men about their identities. They were continuously shouting and menacing the captives with their weapons, he said. “They split us into two groups,” he said. “The first group, they said, ‘We will release you’. The second group, ‘We will keep you for additional investigation.’ They put me in the group that would be released. When they said that, I thought, ‘No, they will kill me. I was sure they would kill me. They were shouting, ‘We will kill everyone who doesn’t listen to us.’ ”

But the gunmen put him and the others in his group back onto the pickup trucks, and drove them elsewhere, the official said. There, he said, they were told to sit on the ground and not to move, and warned that anyone removing a blindfold would be killed. But after ten minutes of silence, he said, one of the men in the group mustered the courage to clear his eyes, and told the others they were safe. They had been left in a rural area on the northern side of Baghdad, known as Sadr al-Canal. “We don’t know why they took us, and why they released us,” the official said. “It’s a terrorist operation with a big criminal ring that planned this.”

Elsewhere on Tuesday, a car bomb exploded near a busy market in the capital, killing ten people and injuring 25 others, an Interior Ministry official said. Late Monday and into Tuesday, clashes erupted between members of the Mahdi Army militia, who claim loyalty to radical Shiite cleric Moktada al-Sadr, and American troops, in Shuala neighborhood, leaving six civilians dead and 13 injuried, an Interior Ministry official said.

Police found 25 bodies dumped across the city on Tuesday, the official said.