Police in Indian-administered Kashmir have detained the owner of a cyber cafe in connection with Wednesday's bomb attack in the Indian capital, Delhi.

An email reportedly sent by the radical group Harkat-ul Jihad al-Islami (Huji) claiming it planted the bomb has been traced to the cyber cafe.

The US state department says Huji is a terrorist group with links to al-Qaeda.

The death toll from the blast has risen to 12 following the death of an injured man. Seventy-six others are injured.

Huji has been accused of carrying out attacks in India, Pakistan and Bangladesh.

The leader of the group, Ilyas Kashmiri, was reportedly killed in a US drone strike in north-western Pakistan in June.

The police on Thursday said they had detained for questioning Mehmood Aziz, owner of a cyber cafe in the Kishtwar area in Indian-administered Kashmir from where the email was generated on Wednesday afternoon.

The email reportedly demands that a man sentenced to death for involvement in an attack on the Indian parliament 10 years ago should not be hanged.

Too early
 
Mr. Aziz had not kept a record of customers visiting the cyber cafe, a police official told the BBC.

Mr. Aziz told the police that a majority of his clients were college students and that a "student with a backpack" had come to the cyber cafe on Wednesday.

Earlier, Prime Minister Manmohan Singh said investigators had some leads on the attack.

But, Mr. Singh said it was "too early to say" which group was behind the attack.

Mr. Singh visited a hospital in Delhi, where the injured have been admitted, on Wednesday night.

"There are weaknesses in our security system and terrorists are taking advantage of them. We have to overcome these. It is a war we must and we will win," he said.

Meanwhile, a 20-member team of the federal National Investigation Agency has begun an investigation into the attack.

Forensic scientists have collected debris for analysis. Police have issued sketches of two suspects.

The bomb was apparently placed in a case near the first security checkpoint at the court, where people were queuing for passes, officials said.

There have been unconfirmed reports in the Indian media that the police are looking for a car which was reportedly spotted near the blast site shortly before the explosion.

The blast at the high court was the second to target the building in five months and came despite a high alert across the city.

Correspondents say it has renewed doubts about India's ability to protect even its most important institutions, despite a security overhaul that followed devastating attacks by gunmen in Mumbai (Bombay) in 2008. (Source: BBC)