LUCKNOW: A blast outside a temple in northern India injured several people, including Hindu worshippers, and caused a small stampede on Tuesday, triggering a security alert across the country.

A police official had initially said one person had been killed, but government officials later said that about 20 people had been hurt in the explosion, including foreign nationals.

“It was a low intensity blast which occurred around 6.20 p.m. (1250 GMT). As a result of the blast 4 to 5 people got injured,” G.K. Pillai, India's top bureaucrat in the interior ministry told reporters.

“Subsequent to that, we understand that there was a small stampede ... as a result of which between 15 and 20 people also got injured. All the injured have been taken to the hospital.”

When asked if the explosion was a militant attack, he said it was “too early to say”, adding that a general alert had been sounded across India.

India remains jittery about the threat of militant strikes, especially since the Mumbai attacks in November 2008 which killed 166 people and raised tensions between India and Pakistan.

TV images showed blood-soaked debris scattered outside a temple by the Ganges river in Varanasi city, considered holy by Hindus and frequented by foreign tourists.

Women were seen sobbing amid overturned tables and chairs.

The blast occurred shortly after an elaborate evening prayer by the river which is usually attended by hundreds of people, including tourists.

“We heard a very massive blast immediately. I saw people running,” Devendra Singh, a witness, told NDTV television.

“I have seen the police, ambulance and the police vehicles coming in ... They have asked us to move and I am moving out from that place and going back to the hotel,” he said.

In 2006, three blasts in Varanasi killed at least 15 people and wounded 60. -- Reuters