Dr Gandhi was attacked by 20-25 unidentified youths, allegedly belonging to SAD-BJP at village Rassolpura Saidan in Patiala parliamentary constituency, officials said.
Dr Gandhi, who is locked in a battle against Congress' Preneet Kaur and SAD's Deepinder Dhillon, was allegedly attacked with sharp-edged weapons.
He received injuries on his head and the vehicle he was travelling in was also damaged, they said, adding attackers were allegedly led by an Akali Dal Municipal Councillor of Ward No 12, Rajinder Singh Virk.
Following attack, Dr Gandhi sat on a dharna along with party supporters.
Meanwhile, police arrested Akali Dal Municipal Councillor of Ward No 12, Rajinder Singh Virk for attacking Gandhi.
Earlier, AAP activists blocked the Patiala-Amritsar highway seeking action against Akali workers involved in the attack. The blockade was lifted after the arrest of Virk.
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