Six men arrested in a suspected terrorist plot against Pope Benedict XVI on his state visit to Britain were released without charge late Saturday night.
The release by Scotland Yard came hours after Metropolitan Police sources said there was "no credible threat' to the pope.
Five of the six who work as street cleaners in Westminster were arrested in a pre-dawn raid Friday after they were overheard at a London garbage depot apparently plotting an attack. The sixth was arrested later in the day.
The Metropolitan Police earlier refused to confirm reports that the men were joking, saying they had to investigate what might have been a genuine threat, BBC News reported.
The men are employed by Veolia Environment Services, a cleaning company contracted by Westminster Council.
At least five of the men are not British nationals, most are thought to be Algerian, the BBC said.
The men, aged between 26 and 50, were arrested on suspicion of the commission, preparation or instigation of acts of terrorism on Friday. The Vatican said the pope was calm despite the arrests and planned no changes to his schedule. But the arrests overshadowed a major address by Benedict to British politicians, businessmen and cultural leaders about the need to restore faith and ethics to public policymaking.
The sixth man, aged 29, was arrested Friday afternoon at a home in north London, police said.
Authorities searched eight homes in north and east London and two businesses in central London. Police said an initial search did not uncover any hazardous items.
Searches of the premises were completed and had not revealed any weapons or suspicious materials, the BBC said.
Vatican spokesman the Rev. Federico Lombardi earlier said that officials traveling with the pope didn’t know much more about the arrests than what the police had said publicly.
"We have compete trust in the police," Lombardi told reporters. "The police are taking the necessary measures. The situation is not particularly dangerous. The pope is happy about this trip and is calm."
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Pope Benedict XVI visits the United Kingdom
The pope has been heavily protected during his four-day visit to Britain, traveling in a custom-built bulletproof car surrounded by security officials.
Four young British Islamists killed 52 people and wounded hundreds when they set off suicide bombs on three underground trains and a bus in July 2005.