American and Iraqi troops in north-central Iraq are in the second day of an operation that has them surrounding and sweeping through the cities of Hawijah and Riyadh, near Kirkuk, American officials said Friday.

The assault, dubbed Operation Gaugamela, kicked off Thursday morning with soldiers from the “Bastogne” 1st Brigade Combat Team, 101st Airborne Division and Iraqi troops from the 2nd Brigade, 4th Iraqi Army Division taking position outside the cities.

According to American officials, the offensive was “requested by local Sunni Arab leaders” and “follows a series of terror attacks in the area, and comes as there are reports indicating the presence of al-Qaida terror cells in the area.”

In the past five weeks, according to a Multi-National Corps-Iraq news release, 31 Iraqi soldiers have been killed in the region, along with six police officers killed three days ago in a Hawijah attack.

“In Hawijah, Bastogne soldiers and Iraqi Security Forces surrounded the city, blocking off escape routes, as another combined force air assaulted into the market in the heart of the city,” a U.S. military news release read.

“The units are cordoning off the area and searching for terrorist forces. Meanwhile, Iraqi security and coalition forces surrounded the village of Riyadh, about 10 miles away, and are also searching that city.”

The operation is named after a battle in 331 B.C. when Alexander the Great drove the Persian army from the city of Gaugamela, according to the release.

Army officials did not have updates on the operation as of Friday evening.