ISLAMABAD (AFP) - The election of a Pakistani bus driver's son as the mayor of London was greeted with celebration on Saturday (May 7) in Pakistan, from where Sadiq Khan's parents emigrated to Britain in the 1960s.

News of Mr Khan's win in the British capital featured on the front pages of all major Pakistani newspapers Saturday, while also causing a stir on social media.

"Congratulations @SadiqKhan 4 being elected mayor of London," tweeted Bilawal Bhutto, leader of the opposition Pakistan People's Party and son of former prime minister Benazir Bhutto. "British Pakistanis need +ve rolemodel."

Rival opposition leader and former cricketer Imran Khan - whose former wife Jemima is the sister of Sadiq Khan's principal opponent Zac Goldsmith - also tweeted his congratulations to the new mayor.

Elsewhere on social media most Pakistanis appeared to greet Mr Khan's win with pride, with messages marking the recent successes of other high-profile British Muslims - including former One Direction member Zayn Malik, who also has Pakistani heritage - going viral on Saturday.

Some could not resist pointing out the irony of the jubilant reaction in the deeply conservative country.

"Pakistani: Sadiq Khan won! Reporter: So you'd vote for a minority immigrant son of a bus driver as Mayor of Karachi? Pakistani: Are you mad?" tweeted newspaper columnist Bina Shah.

Mr Khan has told media that he has relatives in the port megacity of Karachi, where his grandparents reportedly migrated after the partition of India and the creation of Pakistan in 1947, as well as Faisalabad in Punjab and the capital, Islamabad.