CAIRO (AP) — A roadside bomb struck an army vehicle in Egypt's volatile Sinai Peninsula, killing an army captain and a soldier, the military spokesman said Friday. Brig. Gen. Mohammed Samir said on his official Facebook page that another soldier was wounded in Thursday's explosion near the northern city of el-Arish. The militant group Ansar Beit al-Maqdis, which pledged allegiance to the Islamic State group, has claimed responsibility for most of the attacks in Sinai. Meanwhile Egypt's state news agency MENA said police exchanged fire with three gunmen in Cairo on Thursday, killing two of them while the third fled. Three policemen and two passers-by were wounded. MENA said the three gunmen refused to stop their car at a police checkpoint. Later Friday, the interior ministry identified the two killed gunmen as members of Ansar Beit al-Maqdis, saying they were involved in attacks on soldiers in and around the capital. A video posted by Ansar Beit al-Maqdis on a website affiliated with the Islamic State group showed four Egyptians identifying themselves and confessing to collaborating with the army. Two of the four were later shown being shot and killed. The group has posted previous videos showing the killing of suspected collaborators. The video also showed jihadis checking identities of passengers and drivers along what it said was the road between el-Arish and Rafah. The authenticity of the video could not be verified. Last month, an Egyptian court designated the Islamic State group and all its affiliates as terrorist organizations.