Police in northern India are blaming a crude bomb for a blast inside a hospital reception area.

Officials said Saturday at least three people were injured when the explosive detonated underneath a chair in a waiting area of the Jai Hospital in the city of Agra. Earlier, police had said at least six people had been hurt.

Agra Police Inspector General PK Tiwari told the Press Trust of India it was too early to determine whether the blast was the work of terrorists but that bomb squads have been sent to investigate.

Saturday's explosion comes a little over a week after a bomb blast at New Delhi's High Court killed 12 people.

Indian police have detained at least five people in connection with the New Delhi explosion.

There have been several claims of responsibility for the New Delhi attack. One of them, attributed to the terror group Harkat-Ul-Jihad al-Islami, warned that other courts in the country would be attacked unless India repealed the death sentence given to a man convicted in connection with the 2001 attack on India's parliament.

A second claim of responsibility from the domestic group Indian Mujahideen threatened to attack a shopping mall.