Clashes broke out in the Pakistani city of Gujranwala on Friday after gun shots were fired at the vehicle of Pakistani opposition leader Imran Khan as he led an anti-government march to the capital.
Khan's spokeswoman Aneela Khan said Khan was not injured but his vehicle was hit. The convoy was attacked by a stone-throwing mob and police did not intervene, she said.
Television pictures showed local people tearing up posters featuring Khan's party and clashing with his supporters.
Khan and cleric Tahir ul-Qadri are both leading protest marches to the capital, where they intend to hold a sit-in until the prime minister resigns.