Srinagar, Sep 28 (IANS) Eleven persons, including nine policemen, were injured in a powerful hand grenade explosion in the heart of summer capital Srinagar Wednesday afternoon.

Police said separatist guerrillas attacked a joint patrol of police and Indian paramilitary with a grenade in Budshah Chowk near the city centre late this afternoon.

"Nine local policemen, one paramilitary central reserve police force soldier and two civilian passers-by were injured in the explosion. All the injured were immediately taken to SMHS hospital," a senior police officer told IANS here.

He said Budshah Chowk area had been surrounded by security forces and searches mounted.

The explosion led to the disruption of traffic in Budshah Chowk where shops were already shut following Jammu and Kashmir Liberation Front protests during the day.

Earlier, militants shot and killed a police constable and critically injured a police assistant sub-inspector in two incidents in capital city.

No group has yet claimed responsibility for Wednesday's attacks.