Uranium Found in Package at London's Heathrow Airport

The package containing traces of uranium had been sent from Pakistan, via the Gulf state of Oman, and was addressed to Iranian nationals in the UK. The senior counter-terrorism officer reassured residents and travellers that it posed no threat.

An "extremely small" amount of the radioactive element uranium has been detected in a package at London's Heathrow Airport.

The British capital's Metropolitan Police said on Wednesday that its counter-terrorism command was contacted by UK Border Force officers after the item contaminated with the material was discovered on December 29.

The parcel was addressed to un-named Iranian citizens living in the UK and had come from Pakistan, via Oman.

Counter-terror commander Richard Smith said the amount of uranium found "was extremely small" and that experts said it posed no threat to the public at Britain's busiest airport.

"Although our investigation remains ongoing, from our inquiries so far, it does not appear to be linked to any direct threat," Smith said. "As the public would expect, however, we will continue to follow up on all available lines of enquiry to ensure this is definitely the case."

The terrorism chief said the incident highlighted the UK's "excellent capability" to protect its ports and borders and to "keep the public safe from any potential threats to their safety and security that might be coming into the UK."

Uranium is a naturally-occurring heavy mineral with several radioactive isotopes, making it hazardous to handle. When enriched to increase the concentration of the U-235, it can be used as fuel rods for nuclear power reactors — and at very high levels of purity to construct nuclear weapons.