LUCKNOW, India - Nearly simultaneous blasts outside courts in three northern Indian cities killed at least 10 people in what a senior government official said were terrorist strikes.

Police said the blasts were reported from Lucknow, Varanasi and Faizabad, all in the populous state of Uttar Pradesh.

Brij Lal, a senior state police officer, told local television that 10 people had been killed; three in Faizabad and seven in Varanasi.

There was no report of any casualties in Lucknow.

"I believe it is the handiwork of groups who are trying to spread terror in our country," junior Home Minister Sriprakash Jaiswal told reporters.

India has been hit by blasts frequently in recent years and most of them have been blamed by investigators on Pakistan-based Islamist militant groups fighting against Indian rule in Kashmir.

NDTV news channel showed what appeared to be at least one dead man lying on a pavement. Other wounded people were lying nearby or being carried away by passers-by.

One injured man rode away on a motorcycle while a passer-by held a cloth or handkerchief to his blood-soaked head.

While Lucknow is the capital of the state, Varanasi is a popular Hindu pilgrimage centre. At least 15 people were killed and 60 wounded there in three explosions in 2006.

Faizabad is a twin city of Ayodhya, a Hindu holy centre where hard-line Hindu groups razed an ancient mosque in 1992, saying it was built on the birthplace of Hindu god-king Ram.

Ayodhya has since been a flashpoint for Hindu-Muslim tensions across the country and the disputed site was also targeted by suspected Muslim militants in 2005.

Outside the Lucknow court, where police said the explosive was attached to a motorcycle, lawyers gathered after the blast to shout "Down with Pakistan".

The lawyers said they suspected the blast was in retaliation for an attack by a mob on three suspected militants of a Pakistani-based group when they appeared in court a few days ago.

Police said the suspects had plotted to kidnap a top Indian politician.

Last month, a small bomb exploded just after evening prayers at Ajmer, an important and crowded Muslim shrine in north-western India, killing at least two people.

Indian officials say that militant groups target religious centres in an attempt to divide majority Hindus and minority Muslims and spark clashes.