A little-known group that police say has ties to Kashmiri separatists asserted responsibility Sunday for a series of bombings that killed 59 people in New Delhi.

Authorities said they had already gathered useful clues about the near-simultaneous blasts that ripped through a bus and two markets Saturday night. The markets were crowded ahead of the Hindu festival of Diwali, one of the year's busiest shopping seasons.

Investigators reportedly raided dozens of small hotels across India's capital looking for suspects, and police said "numerous" people were being questioned.

The attacks came at a sensitive time as India and Pakistan were hashing out an unprecedented agreement to partially open the heavily militarized frontier that divides the disputed territory of Kashmir to speed relief to victims of the Oct. 8 earthquake.

The agreement was finalized early Sunday, and Indian officials appeared hesitant to quickly blame the bombings on Pakistan-based militants, as they have done in previous attacks. India's accusations that Pakistan was involved in a 2001 attack on the Parliament in New Delhi almost caused a fourth war between the nuclear-armed rivals.

A man called a local news agency in the Indian-controlled portion of Kashmir to say Islamic Inquilab Mahaz, or Front for Islamic Uprising, staged Saturday's bombings, which police said killed 59 people and wounded 210.

The caller, who identified himself as Ahmed Yaar Ghaznavi, said the bombings were "meant as a rebuff to the claims of Indian security groups" that militants had been wiped out by security crackdowns and the earthquake that devastated the insurgents' heartland in the mountains of Kashmir.

A senior police officer in the Indian state of Jammu and Kashmir said the caller's name was not familiar to intelligence agencies, and New Delhi's deputy police chief, Karnail Singh, said the group had not been very active since 1996.

However, while Singh would not comment on the group's assertion of responsibility, he said Islamic Inquilab Mahaz was linked to the Pakistan-based Lashkar-i-Taiba, the most feared of the dozens of Kashmiri militant groups.

In Veligonda, a town in Andhra Pradesh state where a train plunged into a river, rescuers have given up hope of finding additional survivors. Officials say at least 111 people died after flash floods washed away a portion of the track.

The brother of a victim of the New Delhi bombings performs last rites at a crematorium. An obscure militant group said it had carried out the attacks.