At least 12 people, including six soldiers, have been killed after a bus hit a landmine in Indian-administered Kashmir, local police say.

Another 36 people including 19 soldiers or more were reported injured - some critically - in the blast, which happened about 75 kilometres (45 miles) south of the city of Srinagar.

The injured soldiers were flown to hospital in Srinagar by helicopter.

Separatist rebels were immediately suspected of planting and triggering the device.

"[The soldiers'] bus hit the landmine and then tumbled down the mountain into a stream," a policeman said.

A truck following behind was also hit by the explosion.

Violence escalates

Vehicles travelling on the busy route were stranded as police cordoned off the road - which links Srinagar to Jammu - to search for militants, the AFP news agency reports.

Sayeed's calls for the violence to stop go unheeded

Violence has returned to the troubled region after a short lull following the appointment of reformist Mufti Mohammed Sayeed as state leader on 2 November.

Also in Kashmir on Saturday, a soldier and a rebel died in a shootout in Gutchi, a village 90 km north of Srinagar, the Associated Press news agency reports.

It says another soldier was killed in nearby Lolab in a separate shootout between security forces and rebels.

On Friday two rebels stormed a security camp in central Srinagar and killed six paramilitary personnel in a two-hour battle before being shot down and killed.

Lashkar-e-Taiba - a hardline Islamist group - claimed responsibility for Friday's attack.