A homeless Egyptian man stabbed an American citizen in the neck with a knife near the American embassy in Cairo's Garden City district Thursday, according to Al-Ahram Arabic language news website.
Local residents in the neighbourhood helped the embassy's security personnel arrest the man as he was trying to escape.
Cairo's security chief referred the suspect to the general prosecution for investigation.
Embassy doctors provided aid to the American citizen and facilitated his transfer to a hospital. The motives of the attack remain unclear.