Police kept hundreds of protesters at bay as they attempted to destroy a field where genetically modified wheat is being tested in Hertfordshire. Mounted officers helped bring activists to a halt in front of the entrance to land owned by the Rothamsted research institute [...] Hertfordshire police handed out leaflets at Harpenden station warning that St Albans council had forbidden “trespassory assembly” under section 14A of the Public Order Act as anti-GM campaigners gathered in a park next to the estate.