Gunmen stormed a prison in Moslem west Beirut before dawn Wednesday and freed at least 180 murderers, drug dealers and other inmates, police said. One officer was killed in one of the most daring attacks ever carried out in the chaos-plagued country. Police believe the 20 raiders were from the mainly Druse Progressive Socialist Party. Police captured more than 100 of the fugitives after searching the Al Zarif neighborhood near the prison. Syrian troops manning a roadblock some 50 yards from the prison made no attempt to foil the attack, police said.