NEW DELHI — Indian authorities are investigating a deadly car explosion in New Delhi under an anti-terrorism law, officials said Tuesday, as forensic experts worked to determine the cause of the blast.

The explosion near the historic Red Fort in India’s capital on Monday killed eight people and injured at least 19 others, police in New Delhi said.

A case was registered under the Unlawful Activities (Prevention) Act, India’s main anti-terrorism law, according to police officials. The law allows broader powers to investigating agencies to detain suspects. The officials spoke on condition of anonymity because of the sensitivity of the case.

Prime Minister Narendra Modi, who was on a scheduled visit to Bhutan on Tuesday, said investigators would “get to the bottom of this conspiracy.

“The conspirators won’t be spared and all those responsible will be brought to justice,” Modi said.

The explosion occurred just before 7pm local time on Monday evening and is believed to have originated from a Hyundai i20 car that had stopped at a traffic signal, Home Minister Amit Shah said. The blast triggered a fire that engulfed several nearby cars and rickshaws.

New Delhi's international airport, metro stations and government buildings were placed on a high security alert after the explosion, the government said.

Images from the scene showed some shattered windowpanes and mangled pieces of vehicles while plumes of fire billowing from the burning cars.

A former imperial palace, the Red Fort is a major tourist attraction in the Old Delhi section of the city. Local media footage showed damaged vehicles and a police cordon at the site.

Home Minister Shah, who visited the site, said “all angles” were being investigated and that security agencies would reach a conclusion soon. He said footage from cameras in the area would form a key part of the investigation.

“We are exploring all possibilities and will conduct a thorough investigation,” Shah said.

The 17th-century Red Fort monument is one of India’s most high-profile tourist attractions. Located six kilometers from the Parliament, it is where Indian prime ministers deliver their annual Independence Day speeches on 15 August.

The area around Red Fort is typically crowded, serving as a main route to the bustling bazaars of the old city. — Euronews