Nearly 300 climate change activists have been arrested after roads were blocked in central London, amid protests aimed at shutting the capital.
A second day of disruption took place after Extinction Rebellion campaigners camped overnight at Waterloo Bridge, Parliament Square and Oxford Circus.
Up to 500,000 people were affected by the diversion of 55 bus routes.
The Met said 290 people had been arrested. During protests in Edinburgh, 29 arrests were made.
Organisers said protests had been held in more than 80 cities across 33 countries.
In London, motorists face gridlocked traffic on a number of alternative routes, such as Westminster Bridge and Blackfriars Bridge.
Transport for London warned bus users that routes would remain on diversion or terminate early.
Mayor of London Sadiq Khan said although he “shared the passion” of the activists, he was “extremely concerned” about plans some had to disrupt the Tube on Wednesday.
“Ongoing demonstrations are causing serious disruption to public transport, local businesses and Londoners who wish to go about their daily business,” Ch Supt Colin Wingrove, of the Met, said.
Campaigners have been ordered to restrict their protests to Marble Arch after they caused widespread disruption on Monday. That order will continue until 21:10 on Friday.
Three men and two women, in their 40s and 50s, arrested on suspicion of criminal damage at Shell’s headquarters in London on Monday, have since been released while inquiries continue.
The majority of the other protesters detained have been held on suspicion of public order offences.