Delhi Police has intensified its probe into a low-intensity blast that occurred near the Israel Embassy here and sources said two youths were caught on camera walking on the road close to the spot shortly before the explosion.

The National Security Guard (NSG) along with forensic experts visited the spot Wednesday morning and collected samples of leaves and grass that they suspected might contain chemicals used in the explosion, police sources said. A team of NSG's dog squad also inspected the spot with two canines, they said.

The team of forensic experts has marked the places with the signage of "A" "B" and "C" from the spot where the low-intensity blast took place on Tuesday.

The experts have used magnetic gadgets to detect the intensity of the blast, said sources.

The officials of Delhi Police Special Cell and local police inspected the spot and a group of paramilitary personnel were deployed there.

An official said as of now the police is contemplating to register an FIR.

The police have also beefed up security in the national capital after the blast near the embassy in Chanakyapuri diplomatic enclave, an official said.

Areas around the Israel embassy and Jewish establishments in Delhi have been put under the watch of the security personnel. The local police have been asked to increase the vigil in the national capital, the official said Wednesday.

According to police sources, CCTV footage have been recovered from near the spot in which two youths were found walking on the road, shortly before the blast. "It is yet to be ascertained whether they are suspects," the official added.

Security agencies have collected multiple CCTV footage from the lanes of Abdul Kalam Road and Prithviraj Road.

Security officials who visited the spot said since no remnants of the explosive were found at the spot, the possibility of a "chemical explosion" cannot be ruled out.

No one was injured in the blast but an "abusive" letter addressed to the Israeli ambassador was found near the site, officials said.

The letter is "abusive" in nature. It has been sent to the forensic lab to check for fingerprints, they said.

"It's a one-page letter written in English. It is suspected to be related to some organisation with name 'Sir Allah Resistence', and the words like Zionists, Palestine and Gaza mentioned in the letter," a police source said Tuesday.

The explosion and the recovery of the letter is a grim reminder of the 2021 blast near the embassy in which some cars were damaged. The National Investigation Agency had probed the case.

Security has been upped around the Israel embassy since the war between Israel and Hamas began earlier this year, the oficials said.

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