The perpetrators of the bombing outside the National Cancer Institute in the Egyptian capital likely used the Telegram messaging app to communicate in carrying out the attack, an audio recording revealed on Friday.

Axar.az reports citing Reuters that in the conversations, a man whose war name is Mohammed Aleesh and someone called Ibrahim Khaled, identified as the brother of the perpetrator behind the car bombing, are heard discussing the whereabouts of the attacker.

“I haven’t been able to contact him,” Khaled is heard telling Aleesh about the attacker.

Egyptian security forces killed 17 "terrorists" during an operation against the suspects in the car blast, the ministry announced.

Telegram has become the most widely used app of its kind by terrorists, an expert on extremist groups, told Asharq Al-Awsat.

Amro Abdelmenhem, another expert, said that “around 20,000 to 50,000 terrorists have dropped Twitter in favor of Telegram.”