Hong Kong police have arrested five more people in connection with a high-profile attack on a prison officer outside a prison in Sai Kung, bringing the total number of suspects to 13.

Chief Inspector Wong Yu-fai of the force’s organized crime and triad bureau said on Wednesday that officers arrested the final suspects, four men and a woman, between Sunday and Tuesday.

Three men, aged between 20 and 29, were suspected of either being among the attackers or being the planner and driver of the attack.

The other man, 51, and the woman, 31, were accused of harboring some of the other suspects.

One of the latest suspects has been charged, while at least two of those recently arrested are expected to be tried soon, Wong said.

The other eight men were arrested shortly after the violent attack on the 50-year-old corrections officer outside Pik Uk Prison on Clear Water Bay Road last week.