Captain Ahmed Radwan, of the Central Security Forces (CSF), was killed and two other police captains, Ahmed Sobhi and Ahmed Abdel-Fattah, were injured during a raid on Friday to arrest the alleged perpetrators of the Helwan attack. Following the raid the Interior Ministry issued a statement saying, “Radwan was killed and Sobhi and Abdel-Fattah were injured during a mission to arrest terrorist elements in South Cairo.” All three are from the ministry's CSF department. A military funeral was held on Saturday for Radwan. Among those in attendance were parliamentary speaker Ali Abdel-Aal, the interior minister and ministry officials. Security sources told Al-Ahram Weekly that an exchange of fire occurred during Friday's security raid, which left three suspects dead. Two others were arrested. On 8 May, eight plainclothes policemen were killed in Helwan by militants. Four armed men dismounted from a truck and shot dead the eight policemen who were patrolling in an unmarked microbus. Following the terrorist attack, Cairo and Giza security directorates joined forces and focussed operations on an area on the outskirts of Helwan. The security raids, which involved Central Security and Special Forces, were launched after information was received that the perpetrators of the attack had fled to the area, which contains desert paths and rocky terrain, making is difficult to police. Security expert Kahled Okasha said the Interior Ministry had successfully imposed a security cordon around the area, which resulted in Friday's “successful raid”. According to Okasha, “The investigation following the terrorist attack indicated that the suspected terrorist cell had hidden in Ezbet Al-Walda.” The Islamic State (IS) and the Popular Resistance have both claimed responsibility for the attack. In a statement circulated on social media networks, IS said the attack was to avenge women imprisoned in Egyptian jails. A Facebook page associated with the Popular Resistance said it had been performed “in honour of the martyrs of Rabaa Al-Adaweya massacre”. Since Mohamed Morsi's ouster terrorist attacks in Egypt have claimed the lives of hundreds of security personnel. Ansar Beit Al-Maqdis — now known as an IS affiliate in Egypt — is thought to be behind most incidents targeting security forces though a number of smaller militant groups, including Agnad Misr, the Popular Resistance and Revolutionary Punishment, have emerged. That the eight policemen were travelling in an unmarked microbus and wearing civilian clothes led some observers to speculate that the attack must have relied on inside information. Media reports appeared claiming that five lieutenant police officers were involved in the attack. Al-Wafd quoted a security source saying: “The five officers had previously refused to take part in the dispersal of the Rabaa Al-Adaweya sit-in and were subsequently removed from the Special Forces.” The source added that “the five officers dropped out of work a week before the Helwan incident” and “left messages to bid farewell to their families”. South Cairo prosecution, however, denied the rumours of police involvement. “The investigation of the security services has yet to identify the perpetrators of the attack,” said Ahmed Al-Abraq, South Cairo's chief prosecutor. He added that the prosecution had not yet issued arrest warrants against anyone. Okasha also denies the involvement of police officers in the attack. “Some newspapers and websites simply repeated claims, without any substantiation, which first appeared on social media platforms,” he said.