The Delhi Police will look into "end-to-end encrypted calls" of active mobile numbers near the Israel Embassy as part of its probe into a low-intensity blast that occurred there on Tuesday night, sources in the police said.
Police have intensified its probe after the blast and have identified two suspects who were caught on camera walking on the road close to the spot shortly before the explosion.
"It is hard to trace end-to-end encrypted calls, but with special investigative techniques and dump of nearby numbers, we can trace who were near and around the area where a low-intensity blast occurred," said a senior police official who requested anonymity.
Police said that there are several different social media applications that need to be checked and concerned companies will be communicated with.
On Wednesday, a team of senior police officers visited the area surrounding the Parliament to investigate if there was any connection between the recent security breach in Lok Sabha and the blast.
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.
Delhi Police have also beefed up security in the national capital and additional security forces were deployed near the border areas to maintain law and order in view of the New Year celebrations and the two incidents.
"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," an official said.
According to the police, they have already started monitoring several CCTV footage of the area.
The experts have used magnetic gadgets to detect the intensity of the blast, said sources.
Police said that they are investigating the case from every angle. "Special teams are checking the registration numbers of all vehicles that passed during the time of the blast and prior to the blast. We will identify the vehicles soon as there are red light posts on both ends of the road," a senior police officer said.
Multiple CCTV footage have been collected from the lanes of Abdul Kalam Road and Prithviraj Road.
Security officials who visited the spot said the possibility of a "chemical explosion" cannot be ruled out since no remnants of the explosive were found at the spot.
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 letter found at the spot is akin to another blast near the embassy in 2021 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, officials said.
