Polling stations have opened in eastern Ukraine for twin referenda on splitting from the rest of the country that have been called by pro-Russian secessionists.

Ukraine's interim president, Oleksandr Turchynov, has called on eastern Ukrainians to vote "no" in the referenda, which threaten to split the country in two.

In Sunday's controversial and hastily arranged ballots, secessionists asked residents of the Donetsk and Luhansk regions to approve the declaration of sovereign people's republics where insurgents recently seized government buildings.

The referenda are not regarded as legitimate by Kyiv or Western powers.

'Step into the abyss'

Separating from Kyiv "would be a step into the abyss for these regions," President Turchynov warned in a post on the government's website on Saturday.

"Those who stand for self-rule do understand that it would mean complete destruction of the economy, social programs and life in general for the majority of the population in these regions," he added.

Kyiv has been struggling to keep the economy afloat for months. Following the ouster of President Viktor Yanukovych earlier this year, the IMF, the US and the EU all vowed financial support to rescue Ukraine from economic ruin. The IMF most recently approved a $17 billion bailout package for the ailing eastern European country.

Moscow's influence

The interim Ukrainian president also warned that the local population had allowed itself to be swayed by "terrorists" who have been acting in the interest of Moscow and Russian President Vladimir Putin.

"A dreadful terror is in train with the support of a large part of the local population," Turchynov said, referring to the occupation of local government buildings by armed pro-Moscow seccessionists across a number of cities in eastern Ukraine.

"It is a complex problem with a population deceived by [Russian] propaganda support terrorists."

The US and other Western countries have told the UN Security Council that Moscow has driven the separatist movement, based on collected evidence which revealed well-coordinated takeovers of municipalities.

Turchynov invited separatists to participate in roundtable talks. However, he rejected the inclusion of "terrorists" in any negotiations.

The US State Department said Washington would "not recognize the results of these illegal referenda." Department spokesperson Jen Psaki said the ballots amounted to "an attempt to create further division and disorder" in Ukraine.

Merkel, Hollande threaten sanctions

The EU is likely to extend its selected sanctions against Russia on Monday over the referenda. European commission member Janusz Lewandoski said Brussels would target about 15 people and several Crimean branches of Ukrainian companies taken over by Russians.

Moreover, the question of whether general elections for Ukraine would go ahead on May 25 also resurfaced on Saturday.

German Chancellor Angela Merkel and French President Francois Hollande on Saturday issued a joint statement threatening Russia with further sanctions if the election did not go ahead.

The two leaders also called on all sides to begin disarming irregular forces in Ukraine under the supervision of the OSCE by May 15 at the latest, and urged Russian President Vladimir Putin to do more to reduce tensions in the country.

Red Cross hostages freed

Tensions remained high in Ukraine on Saturday with news of another abduction of aid workers and fears of more deadly clashes between protesters and police.

Earlier in the day, pro-Russian rebels released nine Red Cross workers who had been abducted the previous evening. Among them were eight Ukrainians and one Swiss national.

Chaotic violence gripped the region on Friday as pro-Russian militants and Ukrainian battled for control of local governments. In Mariupol, at least seven people were killed and 39 wounded, as well as at least 20 pro-Russian militants, according to regional authorities.

kms/jm, ipj (AP, Reuters, dpa)