NA Speaker Raja Pervez Ashraf (L) administers the oath to Hamza Shahbaz Sharif (R) as the chief minister of Punjab in Lahore on Saturday. Twitter photo

The son of Pakistan's Prime Minister Shahbaz Sharif took charge of Punjab province on Saturday, the country's most politically important region, further bolstering the dynasty's grip on power.

Nepotism and cronyism are deeply entrenched in the nation of more than 220 million people, with power mostly shared between two families — the Sharifs and the Bhuttos —for much of Pakistan's history.

National Assembly (NA) Speaker Raja Pervaiz Ashraf administered oath to Hamza Shahbaz as the elected chief minister of Punjab at a ceremony at the Governor House, Lahore, just hours after Governor Omar Sarfraz Cheema rejected Usman Buzdar's resignation, deeming it not constitutionally valid.

Today a month-long political crisis in Punjab has come to an end," the 47-year-old Sharif told reporters after he was sworn in. "I will seek guidance from the prime minister Shahbaz Sharif and will take coalition partners into confidence."

In unprecedented scenes, Buzdar's cabinet was "restored" by Cheema, according to former provincial education minister Murad Raas, which even convened for a meeting, as guests were arriving at the Governor House to attend Hamza Shehbaz's oath-taking ceremony.

The ceremony eventually began with the recitation of the Holy Quran, after which Hamza — clad in a sherwani — was sworn in as the chief executive of Punjab, picking up a mantle held three times by his father, Shahbaz Sharif.

While the ceremony was underway, Cheema urged the chief justice to take notice of the gangsterism at the Governor House. He also said the "drama of a fake chief minister's oath" was being performed in an "unconstitutional" manner.

Security around the Governor House was beefed up and a large contingent of police was deployed there.

Hamza was elected as the chief minister on April 16, during a provincial assembly session that was marred by mayhem and violence. His oath-taking, however, faced delays after Punjab Governor Cheema refused to administer the oath to him, questioning the validity of his election.

Subsequently, Hamza had approached the LHC on April 21, which instructed President Arif Alvi to appoint a representative to administer the oath in the absence of the governor.

However, after a delay by the president in following the court's directive, Hamza moved the court again on April 25. This time, he had asked the LHC to instruct Senate Chairman Sadiq Sanjrani to administer an oath to him. In his ruling, LHC Chief Justice Ameer Bhatti had directed Governor Cheema to complete Hamza's oath-taking process by April 28.

When the president and governor still failed to follow the court's instructions, Hamza sought the LHC's intervention for a third time on Friday.

In his third petition, Hamza prayed the court to "kindly direct the administration of oath to the chief minister-elect by a person nominated by this honourable court at the Governor House at a specified time and the coercive arm of the state be set in motion for implementation of the orders of this honourable court".

On Friday, the LHC directed the National Assembly speaker to administer the oath to Hamza.

In a late-night development the same day, the Punjab government announced that the oath-taking ceremony would be held at Governor House.

Meanwhile, Punjab Assembly Speaker and Pakistan Muslim League-Q (PML-Q) leader Chaudhry Pervaiz Elahi said he would challenge the LHC’s decision on Hamza Shahbaz’s third plea.

Buzdar’s resignation that Cheema has now rejected had been accepted by Governor Chaudhry Muhammad Sarwar before he had resigned and slammed the then Prime Minister Imran Khan.