Separately on Saturday, Czech police said they were searching for two men carrying various passports, including Russian ones in the names of Alexander Petrov and Ruslan Boshirov. Russian Federation has denied involvement in the attack.
Members of the National Centre against Organised Crime of the Criminal Police and Investigation Service (NCOZ) published mugshots of the two suspects who are accused of operating in the country between October 11, 2014 and October 16, 2014.
Czech police are looking for suspects using the identities Alexander Petrov and Ruslan Boshirov in connection with the explosion.
They said the two also visited the capital of Prague and another northeastern Czech region.More news: COVID death toll passes three million as India cases surge
"There is a reasonable suspicion that Russian secret agents of the GRU service were involved in the 2014 explosions of an ammunition dump in the Czech village of Vrbětice", he said.
Hamacek said 18 Russian embassy staff identified as secret service personnel would be ordered to leave the North Atlantic Treaty Organisation country within 48 hours.
He added he had received the information on Friday, without explaining why it had taken so long.
The Czech government is expelling 18 Russian diplomats after concluding Moscow's military intelligence service was involved in a massive 2014 explosion at an ammunition warehouse that killed two people.More news: Chauvin skips testifying as trial in Floyd death nears end
United Kingdom authorities believe the two Russians are responsible for the Salisbury attack.
On Sunday, the EU's executive commission confirmed remarks by acting Czech Foreign Minister Jan Hamacek on Twitter that the dispute would be addressed during a previously schedule European Union foreign ministers' video conference on Monday.
A senior Russian parliamentarian on Saturday called the claim absurd.
Commenting on the decision to expel the diplomats, Jan Hamecek, the Czech interior minister, said: "We are in a similar situation to, for example, Britain with the case of the attempted poisoning in Salisbury". The United States imposed sanctions against Russian Federation this week for interfering in last year's USA election, cyber hacking, bullying Ukraine and other alleged malign actions, prompting Moscow to retaliate.More news: Germany and France agree on climate cooperation with China