British police confirmed Saturday that they had arrested four men in London under new British anti-terrorism legislation. The police used authority from section 41 of the Terrorism Act, which allows a constable to make an arrest without a warrant in certain instances of suspected terrorism.
The men were arrested under suspicion of attempting to purchase "red mercury", a radioactive material developed by Russian scientists during the Cold War. The police made the arrest after a tip from a British tabloid. Read Sunday's News of the World story on the arrests here. Reuters has more.