Four robbers, most of them armed and masked, forced their way into a Brooklyn Center apartment early Monday morning, robbed eight occupants and bound most of them with duct tape, police said.

The crime wasn't random because the robbers, three brandishing semiautomatic handguns, sought and stole a specific, valuable item, as well as cash and cell phones, said Commander Mike Reynolds. He wouldn't disclose what the item was.

One of the occupants told police he was expecting someone else when he heard a knock about 4 a.m. and opened the door.

The robbers, three men and a woman, forced their way in, striking the man on his head. He was treated at North Memorial Medical Center in Robbinsdale, Reynolds said.

The robbers bound six men with duct tape in the apartment, which was in a building across the street from the Brooklyn Center police offices at 6645 Humboldt Av. N. Two female victims were locked in a bathroom, Reynolds said.

The robbers also stole an occupant's vehicle. Police are looking for a tan 2005 Chevrolet Tahoe with the Minnesota plate PNY 459.

At about 6 a.m., one of victims got free and ran across the street to get help at the police station, Reynolds said. Some of the victims were visitors, one a 17-year-old and the rest young adults, he said. He added that they weren't completely cooperative with police.

JIM ADAMS