A policeman was killed and 11 other security personnel injured in a grenade attack in Srinagar on Sunday evening, police said.

Police said militants lobbed a grenade at a security force party in old city's Nowhatta area at around 6.30 p.m. as they were withdrawing from the area after the day's deployment.

"A police constable identified as Shamim Ahmed was killed in the grenade explosion. Eleven other security personnel including eight policemen and three Central Reserve Police Force (CRPF) troopers were injured," said a police officer here.

Earlier reports had said 10 CRPF troopers had been injured in the blast.

"The injured security personnel have been shifted to hospital for treatment. The area has been cordoned off for searches," the officer said.  

The attack came on the day Prime Minister Narendra Modi visited the state to inaugurate the Nashri-Chenani tunnel on the Jammu-Srinagar highway.

Separatists had called for a shutdown to protest Modi's visit.