The European Union on Thursday added five separatist groups and 13 individuals to a blacklist for their role in elections this month in rebel-held eastern Ukraine, diplomatic sources said.
The decision taken by the 28 EU ambassadors "responds to the separatist vote which undermined ... the implementation of the Minsk protocol" establishing a ceasefire in the region, one of the sources said.
An EU source said the blacklist calls for imposing asset freezes and travel bans on the 13 individuals, with asset freezes also slapped on the five "entities".
The names of the 18 were not immediately available and would be published on Saturday, according to EU procedure.
The new blacklist adds to the previous one of 23 entities and 119 individuals facing asset freezes and travel bans.
Those include close allies of Russian President Vladimir Putin, Russian oligarchs and rebel leaders.
The new list will be formally agreed in a "written procedure" by the 28 EU member states on Friday and the names published in the Official Journal of the European Union on Saturday, the diplomatic source said.
EU foreign ministers on November 17 gave the green light for the new blacklist against pro-Russian separatists but gave ambassadors until the end of the month to come up with the measures and names.
The ministers stopped short of fresh economic sanctions against Russia, saying there was hope of restarting dialogue with Moscow to end the worst standoff since the Cold War.
The pro-Russian separatists defied the Ukrainian government on November 2 when they held leadership elections in the east of the country that they described as legitimising their two self-declared independent states.
Russia then said it "respected" the outcome of the elections but conspicuously did not go as far as saying it recognised them.
The EU, Kiev, and the United States all said that the polls had badly damaged the peace process, which was based on giving rebel areas autonomy, not independence.
The EU source said the European ambassadors also heard proposals for "an enhanced ban on investments in Crimea," which Russia annexed from Ukraine in March in defiance of Kiev and the international community.
Discussions will continue within the European Council, which makes up the member states, the sourace said.
The EU has long been divided over sanctions, initially limiting them to individuals after Russia's annexation of Crimea, then broadening them to target the Russian economy after Malaysian Airlines flight MH17 was shot down in July over eastern Ukraine.
Russia has denied backing the rebels but relations with the West are at their worst since the fall of the Berlin Wall 25 years ago.