Pine Bluff police say eight people have been arrested after a raid on a house where undercover officers had made buys of what was believed to be crack cocaine. The arrests were made in the raid about seven o-clock Wednesday night, as officers served and executed a search warrant. Police said they found 16 people inside the house in the city`s south-central area. A news release said the arrests of six men and two women were made on various outstanding warrants, including several from other counties. One of the men arrested was also charged with possession of drug paraphernalia. Officers said the other eight people at the house were released pending further investigation.