A technician was killed in an explosion at a top Pakistani nuclear research facility founded by disgraced atomic scientist Abdul Qadeer Khan, a military spokesman said on Wednesday.
Tuesday's blast at the Khan Research Laboratory (KRL) near Islamabad involved only conventional explosives and not nuclear material, Major General Shaukat Sultan told a news agency.
"The technician was handling normal, conventional material," Sultan said. "It was an accident and the cause of the explosion is being looked into."
KRL, founded by AQ Khan in the 1970s, played a key role in uranium enrichment leading to Pakistan's nuclear weapon tests in May 1998.
Khan admitted in 2004 that he had leaked atomic secrets to Iran, North Korea and Libya. The scientist is being held under house arrest but has been pardoned by President Pervez Musharraf.
Pakistan has barred foreign authorities from interrogating Khan, who has been dubbed the father of Pakistan's nuclear weapons programme and is still regarded as a national hero.