The European Union sanctioned on Monday two senior Russian military intelligence officials and two of their officers blamed for poisoning a former Russian double agent in Britain last year, a decision Moscow dismissed as groundless.

The European Union’s travel bans and asset freezes included two men Britain has named as intelligence officers, Alexander Petrov and Ruslan Boshirov, who are accused of attempting to murder the former spy, Sergei V. Skripal. His daughter was also poisoned.

The men have denied any involvement in the spraying of a chemical weapon on Mr. Skripal’s front door in Salisbury, England, in March.

In response to the case, which has widened the already large diplomatic gulf between Russia and the West, the European bloc also sanctioned the head and deputy head of Russia’s military intelligence agency, the G.R.U., Igor Olegovich Kostyukov and Vladimir Stepanovich Alexseyev.