MOSCOW -- Russia said Friday morning that it was expelling 23 British embassy staff from Moscow. It is Russia's latest move as tension between the two countries escalates rapidly following the poisoning of a Russian former double agent in England.

CBS News correspondent Elizabeth Palmer reports that British Ambassador to Russia Laurie Bristow was summoned on Saturday morning to the Foreign Ministry in Moscow, where he said the Russians informed him of their retaliation for the expulsion of Russian diplomats from London earlier in the week.

High-level diplomatic rifts follow a predictable pattern, says Palmer, and this one is no different; everyone knew Russia's move was coming, it was just a question of when.

The expulsion of 23 British diplomatic personnel from Russia was a tit-for-tat move that mirrored Britain's expulsion of 23 Russian diplomats in the U.K. -- all of whom the British said had been identified as "undeclared" intelligence agents.

In addition, Moscow said it was rescinding permission for the U.K. to open a new consular office in St. Petersburg, and that it was shuttering the British Council, a U.K. government organization based in Moscow and dedicated to cultural and scientific cooperation between the countries.

Soon after the attack on ex-spy Sergei Skripal and his daughter in the English city of Salisbury, the British government accused Moscow of poisoning them with a powerful chemical nerve agent known as Novichok.

Speaking after his meeting at the Foreign Office on Friday, British Ambassador Laurie Bristow said the, "crisis has arisen as a result of an appalling attack in the United Kingdom -- the attempted murder of two people using a chemical weapon developed in Russia."

President Donald Trump joined British Prime Minister Theresa May and the leaders of Germany and France on Thursday to issue a joint statement pinning the blame for the attack squarely on the Russian government. Russia has consistently denied any culpability, accusing Britain of refusing to hand over samples of the poison used.

In London, British Foreign Secretary Boris Johnson went even further on Friday, pointing the finger directly at Russian President Vladimir Putin on Friday.

"Our quarrel is with Putin's Kremlin and with his decision, and we think it is overwhelmingly likely that it was his decision to direct the use of a nerve agent on the streets of the U.K.," Johnson said.

Prime Minister May said Saturday that Britain would, "consider our next steps in the coming days alongside our allies and partners," after Russia's expulsion of the diplomats. She said the March 4 attack on Skripal was a "flagrant breach of international law and the chemical weapons convention."

Skripal's poisoning has prompted police in Britain to re-examine the cases of several Russians who have died or fallen ill on U.K. soil, amid criticism that the British government shut down the original investigations for political reasons without getting to the bottom of what happened.

In what seems like a strange coincidence, police now say Nikolai Glushkov, a Russian former businessman, was murdered last week at his home just outside London. There has been no link drawn yet to the poisoning of the Skripals.

For obvious reason, Russian dissidents in London are spooked.

"That's making a lot of people worried, more worried than it was before," said Russian exile and former cell phone magnate Yevgeny Chichvarkin.

Nobody knows who could be targeted, "who will be next," according to Sergei Kapchuk, a Russian businessman and former politician also now living in Britain. "It's very scary."