At least 10 people were wounded in a grenade explosion in the northeastern Indian state of Assam on Wednesday but no militant group has so far claimed responsibility for the attack, police said, Trend reports citing Reuters.

“It was a grenade blast probably targeted against security personnel conducting routine patrol in the area,” Deepak Kumar, police commissioner in the Assam capital Guwahati, told reporters.

The blast in a busy street in Guwahati occurred at about 8 p.m. (1430 GMT) and those injured included two police officers and eight civilians.

The grenade was lobbed by two people on a motorcycle, Kumar said.

Police said no group had claimed responsibility, but national public radio broadcaster All India Radio said a faction of the banned separatist group United Liberation Front of Asom (ULFA) had claimed responsibility for the attack.

Assam Chief Minister Sarbananda Sonowal condemned the attacks, saying in a tweet he has directed the local authorities to immediately apprehend the culprits.