Police issued a statement saying that the suspect was detained after a group of Jaffa residents attacked officers stationed on Yefet Street.
Officers arrested the 20-year-old who is suspected to have led several attacks on police and property throughout the city since his brother Mahdi was killed last week.
Since the young man's death, riots and unrest have spread throughout Jaffa, with protestors burning vehicles, attacking police and destroying property throughout the city.
The head of the northern branch of the Islamic Movement, Sheikh Raed Salah, visited the Saadi family last Monday and strongly condemned police, saying, "They publicly executed him, there is no justice. Whatever their claims, this behavior is unacceptable. We will not accept this injustice."