Police Sgt. Ted Chun, of the Kalihi District crime reduction unit, said police converged on the house at 2240 Wilson St. shortly after midnight.

"We had a couple of complaints from neighbors about a gambling operation that had been going on in the downstairs part of the house since sometime in May," Chun said.

Undercover police officers were able to make their way into the alleged gambling operation to determine how extensive it was, Chun said.

"It seemed to be attracting 20-plus people per night," Chun said.

Most people arrested this morning were booked on suspicion of promoting dangerous drugs and drug-paraphernalia charges. They were 30 to 57 years old. At least one person was arrested on a parole revocation warrant.

A resident of the house was among those arrested.