Three gangsters suspected to be involved in the Rs 60-lakh bank robbery yesterday escaped after an encounter with the police at Buttar village in the district early today.A senior police officer said they got a tip-off in the wee hours that some suspects had taken shelter in a house at Buttar village. A police party led by ASI Pahara Singh of the CIA staff rushed to the spot. The gangsters started firing with automatic weapons. The police retaliated, but the gangsters jumped over the boundary wall of the house and fled.They sped away in a private SUV that was being used by the cops. The vehicle was reportedly a case property in a hawala racket. A few hours later, the SUV was recovered from Seolani village near Raikot in Ludhiana district.The police picked up brothers Surjit Singh and Ranjit Singh, the owners of the house where the encounter took place, and brought them to the CIA office for questioning.