NEW DELHI - 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.

"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.

(Reporting by Zarir Hussain; Writing by Aftab Ahmed Editing by Frances Kerry) ((Aftab.Ahmed@thomsonreuters.com;))