A blast at a hospital in northern India has injured at least six people.

Police in the city of Agra are blaming Saturday's explosion on what they describe as a crude bomb that was left in the reception area of the Jai Hospital.

Agra Police Inspector General PK Tiwari told the Press Trust of India it was too early to determine whether the blast was a terrorist attack.

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to the terror group Harkat-Ul-Jihad al-Islami, warned that other courts in the country would be attacked unless India repealed the death sentence given to a man convicted in connection with the 2001 attack on India's parliament.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.