JOIN USA Metropolitan Police spokesman said: "Six men who were arrested under the Terrorism Act 2000 on Friday, September 17, were all released without charge late on Saturday night and early this morning."
The men, all believed to be of North African-origin, were arrested on Friday in London. Police searched eight homes in north and east London and two business premises in central London, including a street cleaning depot as part of the investigation.
The Metropolitan Police said the searches of the premises had been completed and had not revealed any weapons or suspicious materials. The men are believed to have been overheard by a colleague as they shared a joke in their canteen.
The Sunday Mirror reported that one of them said: "It would be pretty difficult to shoot the Pope, wouldn't it, as his car is bulletproof?" Another replied: "Yeah, but I bet an RPG would get through that easily enough."
A police source told the newspaper: "When we received the information it was decided that we needed to get the men in and see if there was a real terrorist plot. It wasn't something that we could have taken a chance with, given that the Pope was in the country that day and the men had access to the Pope's route.
"If somebody on a plane jokes that they have a bomb the authorities take it extremely seriously and this was a similar situation. " The arrested men were aged 26, 27, 29, 36, 40 and 50.
One of the men, a 29-year-old, was arrested at a home in north London on Friday afternoon. The other five, believed to be street cleaners, were arrested at gunpoint as armed officers swooped on their base as they prepared to start their shift on Friday morning.
They work for Veolia Environmental Services, a contractor which employs 650 on-street staff to keep the streets of Westminster clean. The cost of policing the Pope's visit will exceed £1.
5 million and is being co-ordinated by South Yorkshire chief Constable Meredydd Hughes.