Four people died and at least 19 more were missing after a boat ferrying them across a swollen river capsized in Indian-occupied Kashmir on Tuesday.

Rescuers in rubber boats joined by marine commandos were scrambling to find survivors as hundreds of worried and mourning family members gathered at the riverbanks after the accident.

The missing included several children who had been on their way to school when the boat overturned in the Jhelum river in the city of Srinagar.

"We have four dead from the tragedy," Muzaffar Zargar, the superintendent for the city's main hospital, told reporters. Three others were being treated, he added.

At least 26 people were on the boat when it capsized, a top official in Kashmir told AFP on condition of anonymity, as they were not authorised to speak to media.

Days of rain across the Himalayan Kashmir valley had swelled the river.

The small vessel had no motor, but its crew propelled it between the riverbanks by pulling a rope fixed at both ends.

Witnesses said the rope snapped with the force of the fast-flowing water, crashing against a pillar of a partially built footbridge nearby.

"I am deeply grieved by the loss of lives due to a boat accident in Srinagar," Kashmir's top political official Manoj Sinha said in a post on social media platform X.

"My thoughts are with the bereaved families," he said, adding that "all possible help" was being provided to relatives of those who died.

Many office workers and schoolchildren take a boat across the river in the morning to avoid road traffic.

Accidents are common on the treacherous roads of the mountainous region but passenger boat disasters are rare.