American's Pakistani kidnappers "sophisticated"

In Pakistan, the search is on for an American who was kidnapped at gunpoint on Saturday in the eastern city of Lahore, near the border with India.

It's not known if the kidnappers were part of a criminal gang or Islamic terrorists.

CBS News correspondent Seth Doane reports that, on Monday, the State Department said the FBI is working with Pakistani and U.S. embassy officials investigating Warren Weinstein's kidnapping.

Weinstein, a 70-year-old business development consultant, worked in Pakistan for the Virginia-based firm J.E. Austin Associates. He had been scheduled to return home to America Monday.

Pakistani police don't know who kidnapped American
American man abducted in Pakistan

A clearer picture of the brazen raid is emerging. Law enforcement sources tell CBS News that three hostage-takers came to the American's front gate offering food to Weinstein's three guards and driver.

After the guards opened the gate, five other hostage-takers, who had climbed over an unguarded rear entrance, showed up carrying AK-47s and pistols, out-gunning the guards.

The eight then tied and gagged the guards and used Weinstein's driver to trick the American into opening the door to his top floor residence.

Jere Van Dyke, a CBS News consultant, was held hostage in Pakistan for six weeks in 2008, said the attack seemed very sophisticated.

"It shows that militant groups can act with impunity right in the middle of the most sophisticated city in Pakistan," Van Dyke says.

Jere Van Dyke's kidnappers didn't make demands for ten days, which is typical, to make sure that authorities don't know where they're hiding. The real fear is Weinstein may have been taken to the lawless tribal region of Pakistan, where he'd be difficult to find.