Two policemen were killed when gunmen opened fire on their patrol vehicle.
当持枪歹徒对巡逻车开枪射击时，两名警察中弹身亡。
《柯林斯英汉双解大词典》
2
The trio were working with special forces carrying out a routine security patrol with Afghan forces when their vehicle was struck by a bomb blast and came under small arms fire.