A National Accountability Bureau (NAB) team on Friday was unable to deliver arrest warrants issued against the Sharif children — Hassan, Hussain and Maryam — at their Jati Umra residence.

An accountability court had on Tuesday issued bailable arrest warrants for Nawaz Sharif's children and son-in-law Mohammad Safdar after they failed to appear before it despite repeated summons.

The presiding judge, Mohammad Bashir, had asked NAB to ensure that the warrants were received, but the NAB team could not find anyone at the residence on Friday to acknowledge their receipt.

The NAB team, headed by Deputy Director Mehboob Alam and comprising Deputy Director Mohammad Kamran and Investigating Officer Imran Dogar, was also met with resistance from the security staff present at the residence, sources in NAB said.

NAB will now request the court to issue non-bailable arrest warrants for the four on October 2, when Nawaz is expected to be formally indicted.

Meanwhile, Nawaz's summons were received by his personal secretary, Qamar Zaman, in compliance with court orders, sources said.

Nawaz had briefly appeared before a NAB court on Tuesday, putting to rest rumours about his decision to not return to Pakistan and face the courts in connection with three corruption references filed against him.

The references followed the Supreme Court's July 28 verdict in the Panama Papers case that had disqualified Nawaz from holding public office.

"Fleeing from the courts is not our way," he had said in a press conference after his appearance in the court.

Maryam, Hussain, Hassan and Safdar are currently in London with the ailing Kulsoom Nawaz, Nawaz's spouse.

Maryam had earlier advised her father to not appear before NAB courts, calling the proceedings against the family a "farce".