Islamabad, May 22 : After spending nearly four years in detention for allegedly transferring nuclear technology to other countries, including Iran and Libya, Pakistan nuclear scientist Dr AQ Khan last evening made his first public appearance when he visited Academy of Sciences amid tight security.

There he reportedly stayed for nearly two hours and met his close friends, including Dr Mubashir-ur-Rehman.

Khan's free movement was possible after the new democratic government relaxed restrictions imposed on him by the previous regime under pressure from the West.

The nuclear scientist was guarded by security personnel of Strategic Command Force (SCF), which provides security to nuclear installations and scientists, reported the Dawn.

During his visit to the Academy, Dr Khan reportedly expressed his concerns over the prevailing political, power and food shortages.

Dr Khan was arrested on Jan 31, 2004 under the Security Act of Pakistan 1952 for allegedly transferring nuclear technology to other countries.

Dr Khan had been asked by President Pervez Musarraf last year to assist the government in power generation, but it is learnt that he had have refused to help. However, the nuclear scientist is said to have agreed to help the coalition government in overcoming power shortage.

According to sources, 95 per cent uranium enrichment was required for manufacturing nuclear arms but for power generation, only five per cent enrichment was needed.