The United Kingdom’s Crown Prosecution Service on Wednesday named and charged two Russian men as suspects in the nerve agent attack on former spy Sergei Skripal and his daughter Yulia in Salisbury in March. Police appealed to the public to share any information on the two men, identified as Alexander Petrov and Ruslan Boshirov.

The Crown Prosecution Service charged the suspects, in absentia, with a conspiracy to murder, attempted murder and use of the nerve agent Novichok.

Prosecutor Sue Hemming said the United Kingdom will not ask Russia to extradite the suspects as Moscow prohibits the extradition of its citizens. “Should this position change, then an extradition request would be made,” Hemming said. “We have, however, obtained a European Arrest Warrant which means that if either man travels to a country where the warrant is valid, they will be arrested and face extradition on these charges for which there is no statute of limitations.”

Hemming said the evidence can be used in court. “It is of course for a jury to decide whether the evidence is enough for them to be sure of the suspects’ guilt,” Hemming said.

Police said the two men flew from Moscow to London on Russian passports two days before the attack on March 4, AP reported. Assistant Police Commissioner Neil Basu said the men were probably using aliases.

The case

On March 4, Skripal and his daughter were found unconscious on a park bench outside a shopping centre in Salisbury, England. They recovered after weeks of treatment.

The poisoning led to a major diplomatic controversy globally. The UK and its allies, including the European Union and the North Atlantic Treaty Organisation, accused Moscow of involvement in the incident and expelled 23 Russian diplomats from their territories. The US expelled 60 suspected Russian spies after the incident.

Russia has repeatedly denied claims that the nerve agent, Novichok, used to poison the pair was developed in the country or the Soviet Union.

In July, a woman died in Amesbury town in South West England after being exposed to the same nerve agent. Amesbury is about 13 km from Salisbury, the place where Skripal was poisoned.

In August, the United States announced its decision to impose sanctions on Russia for its alleged use of a nerve agent.