A gunman has opened fire during an anti-government protest rally in Pakistan, killing one person and wounding seven others including former Prime Minister Imran Khan. Local media say Khan's leg wound was not life-threatening.

Authorities said the shooting occurred in the eastern province of Punjab on Thursday.

Police arrested the suspected shooter immediately after the incident and were looking into a motive.

A spokesperson for Khan's party, Pakistan Tehreek-e-Insaf or "Movement for Justice," called the shooting "a clear assassination attempt." Supporters of the former prime minister are also holding protests across the country.

Khan was ousted as prime minister in a parliamentary no-confidence vote in April.

He began a protest march in the eastern city of Lahore last week, calling for early general elections. The convoy was heading for the capital Islamabad.

The demonstrations came after the election commission disqualified Khan from holding public office for allegedly selling state gifts unlawfully, which he denies.