BAGHDAD – U.S. forces said they foiled a plan by Iraqi militants to bomb a government building using a subterranean tunnel, the U.S. military said on Tuesday.

U.S. forces detained two suspected militants on Monday when they searched a bakery in the city of Mosul, some 390 km (240 miles) north of Baghdad, the U.S. military said in a statement.

They also discovered a tunnel they said was part of a plan by Sunni Islamist al Qaeda to bomb the provincial government headquarters in Nineveh province, where Mosul is located, the statement said.

Mosul police said the tunnel began underneath the bakery.

Photos provided by the U.S. military showed a ladder leading deep into the ground, along with a dimly lit tunnel supported by wooden beams.