Nine Assam Rifles personnel were injured after some unidentified men hurled grenades into a transit camp in Manipur’s capital Imphal on Tuesday evening, the Imphal Free Press reported. This is the second attack on security forces in Imphal this week.

On Monday, there were two grenade explosions at the Polo Grounds, where equestrian championships were being held by the Assam Rifles and Manipur Equestrian Association. Two personnel of the paramilitary force were injured in the attack.

According to the police, Tuesday’s attack took place around 6 pm. While the injured personnel were taken to a hospital, officials did not allow the media to enter the camp, IANS reported.

Chief Minister N Biren Singh condemned the blast, and said steps have been taken to prevent such attacks, the Hindustan Times reported. So far, no arrests have been made and no group has claimed responsibility for the attack.