In 2005, Ahvaz witnessed a number of terrorist attacks, which came following the violent Ahvaz riots. The first bombing came ahead of the presidential election on 12 June 2005. In 2011, another wave of protests by Arab tribes occurred mostly in the urban area of Ahvaz. Before the Iran–Iraq War of the 1980s, the Arabs of Khuzestan mostly resided in the rural regions along the Karkhe and Karun rivers in the southwest of the province and the number living in cities was very limited because the Arab tribes were still following a nomadic lifestyle. But after the end of the war, most of the refuged Arabs were relocated by the government to the urban centres and smaller towns. This conversion of lifestyle directly from nomadic to city life caused many problems and conflicts in the structure of their societies and ultimately has led to some unrest.