"It was a grenade explosion, it has caused injuries to approximately 18 people, all shifted to hospital".
The police and witnesses said that a youth hurled the powerful grenade towards a stationary in J&K Road Transport Corporation (SRTC) bus at the bus terminus at around 11.45 pm.
The area has been completely cordoned off and state police, Central Reserve Police Force (CRPF) have also been deployed at the explosion site.
It is unclear if there were people inside the bus, reported NDTV.
"Some unidentified person today [Thursday] lobbed a grenade at the General Bus Stand here in which 33 persons have suffered injuries", IGP Manish Kishore Sinha said, adding that the injured have been taken to hospital for treatment. All the injured have been hospitalised and five of them are critical, doctors said.
This is the third grenade attack by terrorists in the bus stand area of the city since May previous year.
The blast comes weeks after the February bombing, which was the deadliest attack on Indian forces in a 30-year insurgency by militants seeking either independence for Kashmir or a merger with Pakistan.
Police said Sajjad Bhat, a Kashmiri Indian national from the Hizbul Mujahideen militant group, carried out Thursday's attack.
Tension between India and Pakistan were at an all-time high after the attack. As per latest reports, one terrorist has been killed so far, said reports.
In an ensuing dogfight at least one Indian aircraft was shot down and the pilot captured by Pakistan.