MOSUL, Iraq (AP) -- Lt. Christopher Hanes knew something was wrong as soon as he stepped into the Friends bakery. The oven was unused, the water tank was empty and a large concrete bin was full of dirt that the two employees claimed was used to cool cakes.
Hanes and his soldiers moved the water tank and found the entrance to a 50-foot tunnel heading straight for the nearby provincial government headquarters.
The U.S. military believes insurgents planned to tunnel underneath the compound's blast walls and blow up the headquarters building. With 250-300 Iraqis working in the governor's office and perhaps hundreds more there for business, casualties from such a blast could have been catastrophic.
Discovery of the tunnel Sept. 1, the first day of the Islamic holy month of Ramadan, drove home a message: Sunni militants have been battered but not defeated despite a monthslong operation by U.S. and Iraqi forces to clear Mosul, Iraq's third largest city, 225 miles northwest of Baghdad.
Al-Qaida in Iraq and other extremists are still thinking up ways to launch novel, complex attacks - sometimes working within earshot of Iraqi security forces.
Still, soldiers from the 3rd Armored Cavalry Regiment didn't expect to find anything when they showed up at the bakery. They'd heard from Iraqi informants that the tunnel was there. But not every tip pans out.
"It is not the first time we have responded to tunnel stories," said Capt. Avery Barnett of Carthage, Mo. "And we thought this one would be ridiculous. But it wasn't."
It didn't take long for the troops to realize this time the tip might be right. Two Iraqi men were inside. They appeared calm. But something was wrong.
"As soon as we went inside, you could tell that they weren't baking bread," said Hanes of Grandview, Mo. "I started asking the two men questions, and they were calm, acting like nothing was wrong because the U.S. had been there a few times before."
The first clue was dirt in a bin that was attached to a wall. The soldiers' didn't buy the explanation that it was used to cool cakes.
Troops searched some more. Inside sacks of flour they discovered digging tools. The two Iraqis explained they were digging to install a water pipe.
"Next to the oven, which hadn't been used in a long time, there was a water pipe connected to a water tank that had been very recently painted," Hanes said, suspecting the pipe might be an air hose.
He moved the tank and discovered a pipe sticking out of the concrete. He pulled the pipe - and uncovered the opening to the tunnel.
Hanes and his soldiers descended into the darkened entrance. They found a laser level and a compass so the diggers could make sure they were moving in the right direction. They also found a plastic container that could be reeled back to the entrance to remove dirt.
"I am not a tunnel expert, but it was looking pretty good to me," he said. Every six feet, wooden arches shored up the wall to prevent cave-ins.
Inside the tunnel, troops found a map indicating the militants planned to dig two branch tunnels toward other buildings in the government compound.
"There was a map with targets on it. They were definitely going to drop the provincial hall." Hanes said. "We tested the hands of the two individuals for explosives and they came back positive for TNT."
The two Iraqis were promptly arrested. A U.S. military statement identified them as al-Qaida operatives. American soldiers ran their names through a database of detainees and found their pictures - indicating they had been arrested but released, possibly for lack of evidence or in an amnesty announced early this year.
"When I showed the man with glasses his picture and said `this is you,' he started crying," Hanes said.
Not surprisingly, people in the area claimed no knowledge of what was going on in the bakery.
"They were new guys who rented the bakery and they wouldn't let anyone inside the shop," said Mutab Ahmed Jumaa, who sells tombstones from a shop next door. "I don't know them."
Late that night, a team of Army engineers arrived at the bakery and filled the tunnel with concrete.