Funeral prayers of Pakistani nuclear scientist Dr. Abdul Qadeer Khan has been offered at Faisal Mosque in Islamabad.

According to details, the national hero will be buried in H-8 graveyard as per the decision of his family.

Two separate enclosures were arranged within the mosque premises, of which one catered to the general public and other to the VIPs.

In recognition of his outstanding services for the country and the nation, the government had announced a state funeral for him and as per a notification issued by the Ministry of Interior, the national flag of Pakistan shall fly at half-mast on Sunday.

Known as father of Pakistan's atomic bomb, Dr Abdul Qadeer Khan died on Sunday. He was 85.

He was brought to a hospital Saturday night with complaints of difficulty breathing. He passed away at 6am on Sunday. He is expected to be buried later in the day.

Khan was a pioneer of the country's nuclear program and led it for 25 years. However, he fell out of favor with the military establishment during Gen. Pervez Musharraf’s rule, and was placed under house arrest in 2004. He was later released in 2009.

He is considered a national hero.

Born in 1936 in Bhopal, his family migrated to Pakistan after Partition. He received his undergraduate education at the Technical University of Berlin, his Master's at Delft University of Technology and a Ph.D. in metallurgical engineering from the Catholic University of Leuven.

According to the Atomic Heritage Foundation's profile of Khan, which lists him as a scientist, government official and spy, Khan worked at URENCO, a nuclear fuel company in Holland. He was working there when India tested its first atomic bomb in 1974. Khan wrote to Pakistan's then prime minister Zulfikar Ali Bhutto and offered to work for the country's nuclear program. He stayed in Holland before returning to Pakistan in 1975 "along with stolen gas centrifuge blueprints. The Dutch government opened an investigation into Khan and sentenced him in absentia to four years in prison, although it was later overturned on appeal," the site writes.

Upon his return he set up a lab in Kahuta to develop highly enriched uranium and produced its first HEU in 1982.

Khan was critical of western attempts to sabotage Pakistan's nuclear ambitions. In an oped for Der Spiegel he wrote: "Are these bastards God-appointed guardians of the world to stockpile hundreds of thousands of nuclear warheads and have they God-given authority to carry out explosions every month?”

In 1998, despite international pressure not to test, Pakistan tested its nuclear device.

Although Khan is considered a hero, the US long accused of him of proliferating nuclear materials. In 2003, the US intercepted a German cargo ship on its way to Libya, contenting parts for gas centrifuges. Then Libya's president named Khan as his supplier. A year later Khan admitted to selling those materials and offered his apologies. He was then placed under house arrest until 2009.

A 2005 profile of Khan in The Atlantic writes that he was "convinced that he served his nation honorably, and that even as he transferred its nuclear secrets to other countries, he was acting on behalf of Pakistan."

Many took to Twitter upon hearing the news of his death and praised him for his contributions.

Khan led the country's nuclear program for some 25 years and is considered a national hero in Pakistan.