Nawaz Sharif, the fugitive former prime minister of Pakistan, has returned to the South Asian nation after nearly four years in self-exile, stirring up the country's already fraught political scene as it awaits what is expected to be a tumultuous national election.

Sharif, who has served as Pakistan's prime minister three times and was once ousted in a military coup, landed at Islamabad airport on Saturday, according to airport officials.

Sharif was the former head of the Pakistan Muslim League (Nawaz), or the PML-N, one of two dynastic parties that have traditionally dominated the country's politics.

He was disqualified from holding office in a Supreme Court ruling concerning corruption allegations in 2017.

The following year he was sentenced to seven years' prison for corruption, charges he denied, but the sentence was suspended on medical grounds, allowing him to travel overseas for treatment on the condition that he return within four weeks -- a requirement he then flouted.

His arrival back in Pakistan comes just days after an Islamabad court granted him protective bail, meaning he cannot be arrested before appearing in court.

The development raises the stakes ahead of what is already shaping up to be a fraught election. The South Asian nation has been in a state of political turmoil since the ouster of another prime minister, Imran Khan, a former rival of Sharif.

In recent months, protests have frequently erupted in the streets over Khan's removal, rising prices, and contempt toward the country's powerful military -- which Khan's supporters claim played a role in his ouster, though the military denies this.

Sharif, too, previously blamed his downfall on the military, which has ruled Pakistan for extended periods since its independence in 1947 and retains significant influence. Before the 2017 ruling that ended his third spell in power he had been ousted in a coup, in 1999, and removed as prime minister by a military-backed president in 1993.

Nawaz Sharif's younger brother, Shehbaz, welcomed the news of his brother's bail, writing on Twitter that it was a "fundamental right."

"The elected prime minister, Nawaz Sharif, was disqualified based on a fictitious and fabricated story," Shehbaz Sharif wrote on X, formerly known as Twitter.

"He was implicated in absurd cases and subjected to mistreatment. Any fair hearing would have established his innocence."

Shehbaz Sharif was appointed prime minister in 2022, and remained in the position until August this year, when his government was replaced by a caretaker administration upon the dissolution of parliament ahead of the national election due early next year.

He came to power after the ouster of Khan, who is now behind bars on corruption charges.

Shehbaz Sharif took charge at a time of crippling inflation, soaring fuel and food prices and a struggling economy -- problems that have dented the popularity of the PML-N party. Nawaz Sharif is expected to head its election campaign.