Vijayawada, March 31 : Four policemen were injured in a firecracker explosion at a police station in Andhra Pradeshâ??s Krishna district on Tuesday.

The incident occurred at Challapalli Police Station when the firecrackers stored at the premises exploded.

Four personnel, including a Sub-Inspector, sustained burn injuries. They were rushed to a hospital, where the condition of two of them is stated to be critical.

The police station building was damaged in the explosion. A police vehicle parked in the station premises was also damaged.

According to police, the firecrackers were kept in the station after they were seized by the police recently.

Circle Inspector K.S. Rao visited the scene and examined the cause of the blast.

The firecrackers were seized by the police during the crackdown on illegal manufacturing units and shops during Diwali.

Preliminary investigation by police shows that the firecrackers exploded when a police constable was examining them.

A sub-inspector and three constables were injured in the explosion, which triggered panic among residents in the area.

The injured were shifted to a hospital at Avanigadda. Senior officials visited the spot and also called on the injured at the hospital.

The District Superintendent of Police ordered an investigation into the blast. Following this incident, the police administration is likely to issue directions for the safe disposal of the firecrackers seized and stored at police stations.

A huge explosion in a firecracker manufacturing unit in Kakinada district on February 28 claimed 28 lives. Twenty people, including nine women, were killed, while nine others sustained critical injuries in a powerful explosion at a firecracker manufacturing unit at Vetlapalem village in Samarlakota mandal. Eight of the injured succumbed to their injuries during the treatment.

Following the incident, police and other departments had launched a state-wide crackdown on the firecracker manufacturing units. They sealed illegal units and also inspected the licensed units to verify if they were adhering to all the safety norms.

/IANS