Russian President Vladimir Putin on Friday visited annexed Crimea to boost security measures there, just days after accusing Kiev of attempting an armed incursion into the peninsula.
Putin chaired a meeting of his powerful security council in Crimea as he made his fifth visit to the strategic Black Sea peninsula since annexing it from Ukraine in March 2014.
"We have gathered because of the well-known incident, after stopping an attempt by Ukrainian army sabotage groups to stage an incursion into Crimean territory," he said during the meeting whose aim was to "discuss and implement additional security measures."
Last week, Putin lashed out at Kiev over an incident on the frontier between Crimea and Ukraine, accusing it of "practising terror" and sending a group of saboteurs into Crimea ahead of the elections.
Two Russian officers were killed in the incident, in which Ukraine denied any involvement.
"We have gathered because of the well-known incident, after stopping an attempt by Ukrainian army sabotage groups to stage an incursion into Crimean territory"
Putin, however, continued his accusations Friday, saying "our partners in Kiev have decided to exacerbate the situation" because they did not want to uphold their end of the European-brokered truce agreement signed in Belarussian capital Minsk last year.
Ukraine's President Petro Poroshenko on Thursday said he considered the likelihood of an escalation "high" and could not rule out a "full-scale Russian invasion along all fronts."
Kiev said Thursday heavy rebel shelling killed three soldiers in its east, where the government has been battling pro-Russian separatists since 2014.
Western leaders have expressed alarm over the possibility of an escalation.