Britain demanded on Thursday that Russia provide details about the Novichok nerve agent attack on a former double agent and his daughter after two British citizens were struck down with the same poison.
The two Britons, a 44-year-old woman and a 45-year-old man, fell critically ill after handling what police called a contaminated item near the site of the March attack on Sergei and Yulia Skripal.
Britain has accused Russia of poisoning the Skripals with Novichok – a nerve agent developed by the Soviet military during the Cold War – in what is the first known offensive use of such a chemical weapon on European soil since World War Two.
Russia, which is currently hosting the soccer World Cup, has denied any involvement in the March incident and suggested the British security services had carried out that attack to stoke anti-Moscow hysteria.
“The eyes of the world are currently on Russia, not least because of the World Cup,” British Home Secretary Sajid Javid said. “It is now time that the Russian state comes forward and explains what has gone on.
“It is completely unacceptable for our people to be either deliberate or accidental targets, or for our streets, our parks and towns to be dumping grounds for poison,” he told parliament.
The Kremlin said Russia had offered Britain its assistance in investigating the nerve agent attack and had been rebuffed.
The two Britons taken ill on Saturday were initially thought to have taken an overdose of heroin or crack cocaine.
But tests by the Porton Down military research center showed they had been exposed to Novichok. Britain has notified the global chemical weapons watchdog, the Organisation for the Prohibition of Chemical Weapons (OPCW).