Two bomb blasts killed at least 15 people and wounded 119 others on Thursday in the southern Indian city of Hyderabad, the city's police commissioner, Anurag Sharma, said a day after the attack.

Sharma didn't rule out the possibility of terror involvement in the city blasts. But he refused to identity any group as a suspect.

The two bombs were planted on bicycles parked in a crowded spot, Sharma said. They were improvised explosive devices, he said, and they could have been triggered by a timer.

Prime Minister Manmohan Singh called the strike a "dastardly attack" and said "the guilty will not go unpunished." He directed government agencies to extend all possible relief to authorities in Andhra Pradesh state. He also approved money for the next of kin of those killed and for others seriously injured.