Thousands of opposition supporters had gathered in Tirana as Albania hosts its first EU-Balkans summit, attended by leaders of European Union member states, to protest against the administration of Prime Minister Edi Rama and demand early elections.
As Berisha, who leads the centre-right Democratic Party, walked in front of his supporters waving Albanian and EU flags, a man approached him and punched him in the face.
Berisha had blood on his face but he later addressed protesters in the main square as police in anti-riot gear looked on.
"Our nation is disappearing... Albania is in its worst existential danger in its history. We will save Albania," Berisha told the crowd, pledging to halt the crime and poverty which are driving people to leave the country.
The attacker was beaten by Berisha supporters and arrested by the police.
Police said the attacker had a history of violence and criminal background. The attack was condemned by Prime Minister Edi Rama.
Berisha, a former president and prime minister, is banned from entering the United States over alleged corruption. He denies the charges.
(Reporting by Fatos Bytyci; Writing by Ivana Sekularac, Editing by Alexandra Hudson)
