New Delhi (afp) — India’s defense minister vowed on Tuesday that those responsible for a deadly car explosion in the heart of the capital that killed at least eight people will face justice.

Monday’s blast, if confirmed as an attack, would be the first significant security incident since 22 April, when 26 mainly Hindu civilians were killed at the tourist site of Pahalgam in Indian-administered Kashmir, triggering clashes with Pakistan.

“The country’s leading investigative agencies are conducting a swift and thorough inquiry into the incident — findings of the investigation will soon be made public,” Defense Minister Rajnath Singh told a conference in New Delhi.

“I want to firmly assure the nation that those responsible for this tragedy will be brought to justice, and will not be spared under any circumstances.”

Crime scene investigators scoured through the wreckage of a car early on Tuesday, hours after the intense explosion.

Senior Delhi police officer Raja Banthia said they were investigating the blast, near the landmark Red Fort in the crowded Old Delhi quarter of the city, under anti-terrorism laws.

However, they have not given details on the cause of the explosion, which also wounded at least 19 people when intense flames ripped through other vehicles near the 17th century structure.

New Delhi’s deputy chief fire officer AK Malik told Agence France-Presse (AFP) shortly after the explosion that eight people had been killed.

The Press Trust of India news agency reported on Tuesday that the death toll had risen to 12, although that figure has not been confirmed.

Home Minister Amit Shah told reporters late on Monday that security forces were “keeping all angles open,” adding that it was “very difficult to say what caused the incident” until forensic samples had been analyzed.

At dawn on Tuesday, AFP reporters at the site said police had erected white sheets around the charred remains of vehicles overnight.

Security was increased across New Delhi as both forensic and anti-terrorism agencies searched for evidence.

Prime Minister Narendra Modi offered his “condolences to those who have lost their loved ones in the blast in Delhi” before leaving for a state visit to neighboring Bhutan.

“I understand the pain of the families. The whole nation stands with them,” he said.

The Red Fort is one of India’s most well-known landmarks. Prime ministers address the nation from its ramparts on Independence Day, and its striking features appear on India’s largest banknote.

Eyewitnesses described to AFP how the car exploded in traffic and how people caught up in the surge of flames were set on fire.

“I saw the car explode while it was moving,” said Dharmindra Dhaga, 27.