Pakistan's disgraced nuclear scientist A Q Khan, under house arrest for the past four years after he admitted to proliferating atomic secrets, made a rare public appearance amid tight security after government relaxed restrictions imposed on him.

Khan visited the Academy of Sciences and met some of his old friends, including Mubashir-ur-Rehman. He spent over two hours with them on Wednesday evening.

The federal government has relaxed restrictions imposed on the scientist and he has been allowed to meet his friends, sources said.

During his visit to the academy, Khan reportedly expressed concern at the prevailing power and food shortages in Pakistan.

During the visit, Khan was escorted by security personnel of the Strategic Command Force, which guards nuclear installations and scientists.

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

The 72-year-old scientist has now come out to "rescue the country from the prevailing power crisis by helping the government generate power through its nuclear capability," the Dawn newspaper reported on Thursday.

Khan was asked by President Pervez Musarraf in 2007 to assist the government in its efforts to generate more power but is believed to have refused to help.

However, Khan is said to have agreed to help the new coalition government in overcoming the country's crippling energy crisis.

Foreign Minister Shah Mehmood Qureshi had hinted last month that the new government was considering the lifting of restrictions on Khan.