Coalition personnel mounted two operations last month to rescue three men held hostage in Iraq but did not find them, a U.S. official said yesterday.

British civil engineer Kenneth Bigley and U.S. engineers Eugene "Jack" Armstrong and Jack Hensley were the targets of the rescue. They were kidnapped from their homes in Baghdad on Sept. 16.

The first operation came before Sept. 20, when Armstrong is believed to have been beheaded by his captors, the U.S. official said, discussing sensitive operations on the condition of anonymity. The second came after Armstrong's death but before that of Hensley, which was reported Sept. 21.

CNN reported U.S. forces found no signs of the three during each operation.

Bigley's killing was confirmed Sunday. Another U.S. official said there is credible information that Bigley tried to escape with the help of one of his captors but was recaptured and beheaded.

Tawhid and Jihad, led by Jordanian terrorist Abu Musab Zarqawi, claimed responsibility for the abductions and killings.

More than 150 foreigners have been kidnapped in Iraq, some for ransom and others as leverage against the United States and its allies. Bigley was at least the 28th to be killed.