Twenty-eight people have been charged and 750 arrested in connection with the Extinction Rebellion protests in London.
Police in London are under strain over cell space following the huge number of arrests made during a week of climate change protests by Extinction Rebellion.
Scotland Yard said those released under investigation "will be brought back to be formally interviewed and charged as appropriate in due course".
In a week of disruption in the capital, climate change protesters have glued themselves to trains, blocked Oxford Circus and Waterloo Bridge and protested at Heathrow Airport.
More than 100 police officers have now descended on Waterloo Bridge and have blocked its pedestrian access in a bid to clear the protesters.
Footage from the scene shows a tow truck being reversed onto the bridge, which has now been occupied by Extinction Rebellion for six days.
Extinction Rebellion (XR) has pledged to continue causing disruption until its demands, including the Government declaring a climate change emergency, are met.
The group are now threatening to stage a mass picnic on the Westway road near Edgware Road Tube station on Monday to cause further chaos.
Scotland Yard has condemned the ongoing disruption and has now warned that arrests made during the week are putting police resources under strain.
The force confirmed by midday on Saturday that 718 people have been arrested and 28 people charged. Protests were still under way on Saturday at locations including Oxford Circus, Waterloo Bridge and Marble Arch.
Earlier on Saturday, the force said: "Since Monday, we have made over 680 arrests and of course that places a logistical problem on, and not just, the police service for cell space but also the wider criminal justice system.
"One thing that is unusual about this demonstration is the willingness of those participating to be arrested and also their lack of resistance to the arrests."
In a further warning to demonstrators, who remain camped on Waterloo Bridge, it adds: "We continue to liaise with the protesters - if you want to protest go to Marble Arch.
"There are conditions imposed on the other locations and you will be arrested."
The warning comes after police towed away the group's pink boat from Oxford Circus on Friday evening after it had blockaded the busy junction for five days.
The mast was dismantled behind a police cordon and the boat was towed away to a nearby location as the climate change protesters chanted, "we have more boats".
Hours earlier Dame Emma Thompson, the Oscar-winning British actress, arrived in Oxford Circus and gave a speech to crowds from the boat.
She said: "We are here in this little island of sanity and it makes me so happy to be able to join you all and to add my voice to the young people here who have inspired a whole new movement."
Speaking after to reporters, Dame Emma added: "If you can't have fun whilst saving the planet, what's the point?
"Protest should always have a sense of joy in it because what we are protesting about is saving this extraordinary home of ours and also celebrating the passion and inspiring energy of this young generation."
Earlier, on Friday morning, about 20 activists, most of them under 17, had staged a brief demonstration on roads near Heathrow Airport.
Standing close to a tunnel which leads to terminals two and three, they unfurled a black banner with the message: "Are we the last generation?"
Waterloo Bridge has now been blocked by demonstrators for six days.