LONDON (AP) — Russia's ambassador to the European Union has suggested a nerve agent that poisoned a former spy in England could have come from a British lab.

Vladimir Chizhov says Russia has no chemical weapons stockpiles and was not behind the poisoning of Sergei Skripal and his daughter Yulia.

In comments broadcast Sunday, Chizhov told the BBC that the U.K. chemical weapons research facility, Porton Down, is only eight miles (12 kilometers) from Salisbury, where the Skripals were found earlier this month.

Asked whether he was saying Porton Down was responsible, he replied: "I don't know."

The British government says Chizhov's suggestion is "nonsense."

Meanwhile, Russia's ambassador in London, Alexander Yakovenko, called for "cooler heads." He told the Mail on Sunday that the dispute is "escalating dangerously and out of proportion."