LONDON – British Prime Minister Theresa May said Wednesday that the two suspects charged in the poisoning of an ex-spy and his daughter with military-grade nerve agent were Russian intelligence officers.

It came after the country's Crown Prosecution Service announced the men, known to investigators as Alexander Petrov and Ruslan Boshirov, are charged in absentia with conspiracy to murder, attempted murder, causing grievous bodily harm and use of the nerve agent Novichok.

May told British lawmakers that "based on a body of intelligence, the government has concluded that the two individuals ... are officers from the Russian military intelligence service, also known as the GRU."

Traces of Novichok were found in the London hotel room they stayed in, and "only Russia had the technical means, operational experience and motive to carry out the attack," May said.

Russian Foreign Ministry spokeswoman Maria Zakharova said the names and photos of the suspects “say nothing to us.”

Sergei Skripal, a Russian former spy, and his daughter Yulia were found unresponsive on a bench in the southern English city of Salisbury on March 4 after they came into contact with Novichok, a Soviet-developed nerve agent. Sergei Skripal was jailed in Russia for spying for Britain, but was released as part of a spy swap and moved to Salisbury in 2010.

Britain blames Russia for the poisonings but Moscow denies any involvement.

“We will not be applying to Russia for the extradition of these men as the Russian constitution does not permit extradition of its own nationals," said prosecutor Sue Hemming in a statement.

“We have, however, obtained a European Arrest Warrant (EAW) which means that if either man travels to a country where an EAW is valid, they will be arrested and face extradition on these charges for which there is no statute of limitations.”

Metropolitan Police Assistant Commissioner Neil Basu said authorities were seeking to circulate Interpol red notices about the two suspects, who he said are aged about 40 and likely to have traveled under aliases. He said they flew from Moscow to London and traveled by train to Salisbury to allegedly carry out the attack.

The Skripals were taken to the hospital in critical condition and released weeks later. A police officer, Nick Bailey, was hospitalized after coming into contact with the nerve agent while searching Sergei Skripal's home and was also later released. In July, months after the initial poisonings, Dawn Sturgess, a 44-year-old woman from Salisbury, died a week after she and her partner Charlie Rowley, 48, were found unconscious in Amesbury, a town about 10 miles from Salisbury. British authorities said they were also poisoned with Novichok.

Police believe the nerve agent was smuggled to Britain in a fake Nina Ricci perfume bottle and put on the front door of Sergei Skripal’s house. Rowley found the bottle months later and gave it to Sturgess, who is believed to have sprayed the substance on herself. Rowley spent weeks in hospital before being discharged.

Sturgess was exposed to at least 10 times the level of Novichok that the Skripals came into contact with, Britain's Press Association news agency reported.

"We have now linked the attack on the Skripals and the events in Amesbury which affected Dawn Sturgess and Charlie Rowley. It now forms one investigation," Basu said in a statement Wednesday.

"We do not believe Dawn and Charlie were deliberately targeted, but became victims as a result of the recklessness in which such a toxic nerve agent was disposed of," he added.

Basu urged people in the Salisbury area not to pick up unknown items.

Contributing: The Associated Press

More:Police identify Russian suspects in UK nerve agent attack, report says

More:Who is Sergei Skripal? Russian spy found unconscious in English park sparks intrigue