SRINAGAR (India) • At least 40 Indian security force personnel were killed yesterday and many more injured in the most serious terrorist attack to occur since Prime Minister Narendra Modi came to power.

They died when an improvised explosive device went off as a convoy of military vehicles drove along a highway outside Srinagar, the main city of Jammu and Kashmir state, Asian News International reported.

Central Reserve Police Force (CRPF) Deputy Inspector-General M. Dhinakaran confirmed that at least one bus carrying 39 passengers was attacked as the convoy - which consisted of 77 vehicles and about 2,500 personnel - travelled through Pulwama district, 35km outside Srinagar.

Investigations were continuing into the exact number of dead and injured, he said.

CRPF spokesman Sanjay Kumar said the explosives were inside a car, while local media reports said the explosive-laden vehicle was driven into the convoy.

"It was a powerful explosion. The explosive was car-borne," the spokesman said.

Unconfirmed photos showed the charred remains of at least one vehicle littered across the highway alongside military buses as black smoke billowed upwards.

Local media said the Pakistan-based Jaish-e-Mohammed Islamist group had claimed responsibility for the attack.

A spokesman for the group said the "suicide attack" was carried out by a militant called Aadil Ahmad, alias Waqas Commando, in a statement sent to local media.

The last major car bombing, which killed 40 people - including three suicide attackers - was also carried out by Jaish-e-Mohammed, in 2001. The target of that attack was Srinagar's Parlia-ment building.

Mr Modi condemned the latest attack, which he described as "despicable" in a tweet. "The sacrifices of our brave security personnel shall not go in vain," he said.

Government minister Arun Jaitley said in a tweet that those responsible "will be given an unforgettable lesson for their heinous act".

Yesterday's attack was the deadliest on Indian forces in the country's part of Kashmir since September 2016, when 19 soldiers were killed in a pre-dawn raid by militants on the Uri army camp.

India blamed militants in Pakistan for that attack, the biggest in 14 years, and responded by carrying out strikes across the heavily militarised Line of Control, the de facto border dividing the nuclear-armed nations.

India has an estimated 500,000 soldiers in Kashmir, which has been divided between India and Pakistan since independence from Britain in 1947. Both countries claim the disputed territory in full.

BLOOMBERG, AGENCE FRANCE-PRESSE