A teenager was killed and 32 others were injured on Thursday in a grenade attack by suspected terrorists in the crowded general bus stand area in the heart of Jammu, officials said.

Mohammad Sharik, 17, a resident of Hardiwar in Uttarakhand, who was among 33 people brought to a hospital, succumbed to splinter injuries in the chest, the officials said, adding that the condition of four more people was 'critical'.

The injured included 11 residents of Kashmir, two from Bihar and one each from Chattisgarh and Haryana, the officials said

This is the third grenade attack by terrorists at Jammu bus stand since May last year.

Inspector general of police, Jammu, M.K. Sinha said a preliminary investigation suggested that someone lobbed the grenade in the bus stand area around noon, causing the explosion.

The scene of the blast along B.C. Road was sealed off by the police and a massive hunt has been launched for the person responsible, Sinha told reporters.

A parked bus of the State Road Transport Corporation suffered extensive damage in the blast, which caused panic among the people.

Immediately after the explosion, people ran to safety. Later, as the situation returned to normal, they shifted the injured to hospital.

'The blast occurred on the roadside when there was a huge rush of people. I had come to drop my wife who was going to board a bus to Punjab,' one of the injured, Kuldeep Singh, a resident of the Pragwal area in the city, said.

Singh, who is undergoing treatment along with his wife at the Government Medical College Hospital, said he felt somebody had hurled something, which caused the powerful explosion.

People injured in the grenade attack being brought to hospital in Jammu on Thursday. PTI

Police parties along with sniffer dogs and forensic experts rushed to the spot and launched a search operation, officials said, adding that it was still on when the last reports were received.

No one has been arrested in connection with the blast so far, they said.

'Whenever there is a heightened state of alert, we strengthen checking and frisking, but there is always a possibility of someone slipping through, and this one seems to be a case like that,' Sinha said.

'Obviously, the intention is always to disturb communal harmony and peace,' he added, and requested people to maintain calm.

Singh said the police are collecting the evidence and 'we are sure to hunt him down (the attacker).'

On December 28-29 last year, suspected terrorists carried out a grenade attack at the bus stand with the intention to target the local police station building. Seven months before that, on May 24, 2018, another grenade strike along B.C. Road had left two policemen and a civilian injured.