Indian security forces launched a massive hunt on Wednesday for militants suspected of killing 26 men at a tourist destination in India-held Kashmir in the worst attack on civilians in the country in nearly two decades, with New Delhi pledging a strong response.

At least 17 people were also injured in the shooting that took place on Tuesday in the Baisaran valley in the Pahalgam area of the scenic, disputed Himalayan territory. The dead included 25 Indians and one Nepalese national, police said. It was the worst attack on civilians in India since the 2008 Mumbai shootings.

Modi cut short his two-day visit to Saudi Arabia and returned to New Delhi on Wednesday morning. Finance Minister Nirmala Sitharaman was also cutting short her visit to the United States and Peru "to be with our people in this difficult and tragic time", her ministry said.

Modi held a meeting with the national security adviser, the foreign minister and other senior officials at the airport and a special security cabinet meeting was called for 1230 GMT, a defence ministry official said.

"We will not only reach those who have perpetrated this incident but also those who, sitting behind the scenes, have conspired to commit such acts on the soil of India," Indian Defence Minister Rajnath Singh said ahead of the meeting.

"There will be a loud and clear response soon," he said at a memorial lecture for a former Indian Air Force chief.

India has in the past accused Pakistan-based groups for attacks in India, including those in Mumbai. Pakistan denies the accusations and says it provides moral, political and diplomatic support to Kashmiris.

Hunt for attackers

Security forces rushed to the Pahalgam area soon after the attack and began combing the forests there, two security sources told Reuters. About 100 people, suspected to have been militant sympathisers in the past, were called to police stations and questioned, they added.

Police also released sketches of three of the four suspected attackers, who were dressed in traditional long shirts and loose trousers and one of them was wearing a bodycam, one security source said. There were about 1,000 tourists and about 300 local service providers and workers in the valley when the attack took place, he said.

A little-known militant group, the "Kashmir Resistance," claimed responsibility for the attack in a social media message. It expressed discontent that more than 85,000 "outsiders" had been settled in the region, spurring a "demographic change".

Also Read: 26 tourists perish in Pahalgam after midday shooting

In a fresh statement on Wednesday, the group said that the "individuals targeted were not ordinary tourists; instead, they were linked to and affiliated with Indian security agencies" and said it would step up its activities.

"It was not a typical tourist group but rather an undercover agency tasked with research," it said and added that the attack should "serve as a wake-up call not only for Delhi but also for those who support Delhi’s questionable strategies".

India's government has not commented on the group's claims.

"We are concerned at the loss of tourists’ lives," Pakistani Foreign Ministry spokesperson Shafqat Ali Khan said in a statement. "We extend our condolences to the near ones of the deceased and wish the injured a speedy recovery."

Kashmir shutdown

On Wednesday, over a dozen local organisations called for a shutdown in the federal territory to protest against the attack on tourists, whose rising numbers have helped the local economy.

Many schools also suspended classes for the day in protest.

The shutdown was total and protesters turned out in several locations shouting slogans such as "Stop killing innocents", "Tourists are our lives", "It is an attack on us".

"I want to say to the people of the country that we are ashamed, Kashmir is ashamed," former Jammu and Kashmir Chief Minister Mehbooba Mufti said in a statement. "We are standing with you in this time of crisis."

Also Read: Pakistan 'concerned' over killing of tourists in IIOJK's Pahalgam

Airlines were operating extra flights from Srinagar, the summer capital of the territory, as visitors were rushing out of the region, officials said.

"It’s heartbreaking to see the exodus of our guests," serving Chief Minister Omar Abdullah said on X, adding that the main highway connecting Srinagar to the rest of the country which was damaged by heavy rain had been opened for one-way traffic out of Srinagar to help tourists leaving by road.

While some local tourist operators said they were already getting cancellations for the upcoming peak summer season, the local unit of the Travel Agents Federation of India condemned the attack.

"We will continue to encourage travel to the Valley and stand strong against those who seek to spread fear and unrest," local unit chairman Shamim Shah said in a statement.