The United States on Monday expelled 60 Russian diplomats and said it would close a consulate in Seattle in support of the United Kingdom’s claim that Moscow was behind a nerve agent attack on a former Russian spy living in England. In response, a Russian lawmaker hinted that Moscow could do the same, RIA news agency reported.

The US called the expelled Russian spies, and justified the closure of the consulate by citing its “proximity to one of our submarine bases and Boeing”.

“This attack on our ally, the United Kingdom, put countless innocent lives at risk and resulted in serious injury to three people, including a police officer,” the State Department said, according to the BBC. It also called the incident an “outrageous violation of the Chemical Weapons Convention and breach of international law”.

On Friday, leaders of the European Union had also decided to put up a united front against Moscow and recalled its envoy to Russia for consultations. Germany, France, Poland, Lithuania and Ukraine have also announced they are expelling some Russian diplomats.

The attack

On March 4, former Russian double agent Sergei Skripal and his daughter Yulia were found unconscious on a bench outside a shopping centre in Salisbury, England. After British authorities concluded that it was a nerve agent that rendered them critically ill, UK Prime Minister Theresa May expelled 23 Russian diplomats from the country.

Russia has maintained innocence, claiming to have no hand in Skripal’s poisoning. President Vladimir Putin said it was “total rubbish, drivel and nonsense” that someone in Russia would carry out such “antics” so close to the country’s presidential election and the football World Cup in June.

In response to action by the UK, Russia had ordered an equal number of UK diplomats to leave the country within a week.