UK police close a number of bridges in central London as precaution

British police closed a number of bridges in central London on Tuesday, covering a roughly one mile stretch of the River Thames, saying it was a precaution while they assessed an unattended item.

The bridges were Westminster Bridge, Waterloo Bridge and the Hungerford and Golden Jubilee footbridges. "A number of bridges in central London have been closed as a precaution while officers assess an unattended item in the vicinity of South Bank," Police said on twitter. They did not provide any further information when contacted by Reuters.

Britain last week lowered its national terrorism threat level from severe to substantial, meaning an attack was considered likely rather than highly likely.