Russian anti-Putin anger spreads: 'We have to protest'

Filip Kuznetsov spent an entire night crammed into a police van with 17 other protesters because Moscow's detention centres were all full.

He was among a record 4,002 people arrested across Russia last week, as large crowds took to the streets to demand the release of the opposition politician Alexei Navalny. Further protests have been called for Sunday, threatening to strain the system even further.

"We didn't sleep all night. One person always had to stand for space, so we took it in turns," Filip told me by phone on Wednesday from the back of the police van, which he described as an "ancient vehicle with metal bars all round".

Anti-corruption campaigner Alexei Navalny, fiercely critical of the Kremlin, was imprisoned on his recent return to Russia after recovering from an attempt to kill him with a nerve agent.