The ruling Pakistan Muslim League (Nawaz group) won the highest number of seats in the Senate, upper house of the parliament, local media reported. The PML(N)-backed candidates won majority seats,11 out of 12, in Punjab, the country's most populous province and the party's political powerbase, whereas it also clinched all the two seats from the capital Islamabad, according to unofficial results of the by-elections reported by the state-run Pakistan Television.

Opposition Pakistan People's Party (PPP) secured 10 out of 12 seats from the southern Sindh province which has long been its stronghold, turning out to be the second largest party in the 104-member house elected by four provincial assemblies, and the lower house.

The PPP's Mian Raza Rabbani, who is the current chairman of the senate, also retained his seat from Sindh province.

Pakistan Tehrik-e-Insaf (PTI) of the country's former cricketing hero Imran Khan appeared to be the third largest party in the Senate by winning majority seats from northwestern Khyber Pakhtunkhawa (KP) province.

Most of the seats from southwestern Balochistan province, and semi-autonomous tribal region along the Afghan border were won by the independent candidates.

Following the by-polls results, the PML(N) whose leader Nawaz Sharif was first disqualified by the country's top court in the whistleblower Panama papers scandal in July 2017 from the premiership, and later from the party leadership last month, appears to be the single largest party in the Senate with 33 seats.

But the party will require 20 more votes from its allied parties to clinch the office of the Chairman Senate.