Al-Shabab militants killed two of their accomplices who had been detained by Kenyan security officers when they raided a police camp in Wajir County near the border with Somalia on Tuesday evening.

Northeastern regional police commander Paul Soi confirmed the incident on Wednesday, saying three police officers were injured during the gunfight with the extremist group suspected to have crossed from Somalia.

Soi said there were plans to transfer the suspects to another station before the militants stormed the Dadajabula police station.

The police and witnesses said it was raining heavily at the time of the raid, forcing the police officers on duty to take cover, giving way for the attackers to raid the station at around 8 pm.

“It seems they were high-value suspects. They were pulled from the cells and killed,” said a local official who did not want to be named. He said the raid was about rescuing two al-Shabab suspects the police detained at the station.

The station is about 13 kilometers from the Kenya-Somalia border. The border is porous that could allow in terrorists freely.

Local police said the attackers used rocket-propelled grenades in the attack scaring officers on duty.

The officers called reinforcement from the military but by the time the backup team had arrived, the militants had accessed the police cells and killed two men who were held there over terror-related incidents.

Police believe the attackers were on a rescue mission after the arrest and detention of the two men who were later slain. The suspects had been detained at the station hours earlier over terror-related issues, police said.

A female civilian was also injured in the attack alongside two police officers and a police reservist. The station was burnt in the attack. One of the police officers was shot in the hip, with the bullet exiting, while the other has a bullet lodged in his stomach.

The incident comes days after Somalia authorities handed over to Kenya two men believed to be members of al-Shabab terror group.

The county and other parts of northern Kenya have been subjected to successive explosive attacks by al-Shabab operatives in the country following the onslaught by Kenyan soldiers on the al-Shabab in southern Somalia.

The police believe that the militant group still remains the major threat in areas along the common border, noting that the targets include security personnel, and establishments along the border as well as commuter vehicles plying routes along the border and coastal regions.