BEIJING, May 26 (AFP) - Police have arrested three men for a bomb attack which killed four police officers last month in northern China, a report said Wednesday. The suspects, two from the central city of Luoyang and one from Beijing, were arrested last Friday, the China Police Daily said. On April 20, the three, whom the paper said were planning to rob a bank in Yinchuan in the northern Moslem autonomous region of Ningxia, placed a bomb under a car and lured police to it. The newspaper said they detonated the bomb as the police passed by in their car, killing four officers. The suspects then killed two accomplices before fleeing, it reported. On May 17 the trio killed a man who was sharing their rooms in the southern city of Foshan after robbing him of his money. After the murders of the police, people in Yinchuan collected 1.34 million yuan (160,000 dollars) for their families. The officers who arrested the three suspects were awarded 200,000 yuan, the newspaper added.  