Pakistan has expressed its concern regarding the attempted illegal sale of six kg of uranium in India, and has called for a thorough investigation of such incidents.

In a statement, the Foreign Office (FO) said a similar incident had been reported in India last month when two people were arrested with seven kg of uranium.

"Such reports in the past are a matter of deep concern as they point to lax controls, poor regulatory and enforcement mechanisms, as well as possible existence of a black market for nuclear materials inside India," the FO said.

The FO statement further said that the United Nations Security Council Resolution 1540 and the IAEA Convention on the Physical Protection of Nuclear Material make it binding on 'states to ensure stringent measures to prevent nuclear material from falling into wrong hands'.

It is equally important to ascertain the intent and ultimate user of the attempted uranium sale given its relevance to international peace and security as well as the sanctity of global non-proliferation regime, FO added.

On Friday, Indian police arrested seven people in Jharkhand’s Bokaro city, who were trying to sell about six kg of uranium. The people who were arrested are suspected to be part of a national gang involved in illegal uranium trade, Times of India reported. The police said the suspects were searching for customers and had fixed its price at INR five million.

Last month, two men were also arrested in the western Maharashtra state for possessing the highly radioactive substance.