INDIAN communists today condemned the “dastardly” bomb attack in New Delhi on Monday as authorities investigate under an anti-terrorism law.

The explosion, which occurred near the historic Red Fort, a former imperial palace and major tourist attraction, killed at least eight people and injured several others.

Senior police sources said a case was registered under the Unlawful Activities (Prevention) Act, India’s main anti-terrorism law, which allows broader powers to investigating agencies to detain suspects.

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,” Mr Modi said.

In today’s statement, the Communist Party of India (Marxist) said: “The Polit Bureau of the CPI(M) strongly condemns the dastardly bomb attack in the heart of the national capital, Delhi.”

After expressing “heartfelt condolences” to the families of those killed in the blast, the CPI(M) said: “It is deeply disturbing to learn from reports that large quantities of explosives and firearms have been discovered in areas around Delhi, which are now being linked to the attack.

“This indicates the involvement of an organised network. It is the responsibility of the government to uncover it and bring all the perpetrators to justice.”

The CPI(M) called on the population “to be vigilant, maintain peace and harmony without succumbing to any provocations.”

Police said the explosion was believed to have originated from a Hyundai i20 car that had stopped at a traffic signal. Nearby vehicles were badly damaged, and photos showed shattered windows, twisted metal and flames engulfing several cars.

Police were trying to trace the car’s owner. There was no immediate information about the occupants, who were believed to have been killed.

Home Minister Amit Shah said on Monday that “all angles” were being investigated and that security agencies would reach a conclusion soon.