Updated

Ukrainian national guardsmen opened fire Sunday on a crowd outside a town hall in eastern Ukraine as pro-Russian separatists went ahead with scheduled "self-rule" referendums in two regions, inviting further condemnation from the Kiev government and its Western allies.

Polls opened at 8 a.m. local time (1 a.m. EDT) in the Donetsk and Luhansk regions and were scheduled to close at 10 p.m. (3 p.m. EDT). A pro-Russian election official in Donetsk described the turnout to Fox News as "colossal."

"What do you expect," he asked, "when people are shooting at us?"

The voting took a bloody turn when Ukrainian national guardsmen fired on a crowd outside a town hall in Krasnoarmeisk, and an official with the region's insurgents told The Associated Press there were deaths. It was not immediately clear how many.

Witnesses to the shooting posted a number of videos on YouTube. One of the videos shows several armed men holding AK-47s yelling to the crowd "go home, get out of here." One then cocks his weapon, and seconds later a man from the crowd steps forward and approaches another gunman, also carrying an AK-47, to speak with him. The gunman fires a warning shot over his head, but that doesn't deter the man. He continues to approach as shots continue and the man is struck by a bullet, falls to the ground and can be seen bleeding from his leg.

The video, shot by someone at the scene of the confrontation, has been authenticated based on accounts by AP journalists at the site and was consistent with AP's own reporting on what happened.

The shooting took place hours after dozens of guardsmen shut down the voting in the town.

Separatist fighters in both regions have occupied government buildings in a number of towns since Russia's annexation of Crimea in March. In the process, rebels have clashed with police and regular Ukraine troops.

Insurgents in the city of Slovyansk, which has seen some of the most violent clashes between pro-Russian militants and government forces in recent weeks, exchanged fire with Ukrainian troops on the outskirts of the city overnight. The Ukrainian Defense Ministry said an army soldier was wounded in a mortar shelling near Slovyansk TV tower.

And the port city of Mariupol on the Sea of Azov has remained on edge after Friday's clashes, in which at least seven died.

In Donetsk, there were no disturbances reported as morning became afternoon, though some security was present at voting stations.

Pro-Russian insurgents in eastern Ukraine said preliminary results of the referendum show nearly 90 percent of voters have supported sovereignty for their region.

Roman Lyagin, election chief of the self-styled Donetsk People's Republic, told The Associated Press that around 75 percent of the region's 3 million  voters cast ballots Sunday.

With no independent observers monitoring the vote, however, verifying the figures will prove problematic.

Separatist electoral commission officials in Donetsk told Fox News they will likely release details of today's vote on Monday afternoon.

The referendums, which seek approval to establish so-called "sovereign people's republics" in both regions, are going forward despite a recommendation from Russian President Vladimir Putin earlier this week that they be postponed. The Kiev government has repeatedly accused Russia of fomenting the ongoing unrest in the east, accusations that Moscow has repeatedly denied.

Election organizers said more than 30 percent of voters cast ballots in the first three hours of voting, but with no international oversight mission in attendance, confirming such claims is likely to be all but impossible.

At one polling station in a school in Donetsk, turnout was brisk in the first hour of voting. All voting slips that could be seen in the clear ballot boxes showed that the option for autonomy had been selected.

The haphazard nature of the referendums was in full display at Spartak, a leafy village on the northern fringes of Donetsk.

Villagers were unable to vote for about three hours after polls opened as election officials had failed to bring in the ballot box.

After some arguing between local people and the head of the village council, an election organizer arrived with a voting urn crudely fashioned from cardboard boxes and sealed with tape. Outside the polling station, set up in a village club, one local man complained volubly over the quality of the ballot box as cows basked in the bright sunshine.

Many voters said they hoped the vote would help stabilize the situation.

"I just don't have the words to express what is happening in our country," said the 65-year old Liliya Bragina. "I have come so that there will be stability, so that there will be peace."

The polling station's head, Andrei Mamontov, said he was certain the vote would be fair and not marred by falsification.

"In this polling station, everything will be fine, but I can't speak for other polling stations," he said. "We have prepared everything, we have signed everything, we have done all the checks -- everything should be legitimate and clean."

Organizers of Sunday's vote have said that only later will a decision be made on whether they would use their nominal sovereignty to seek full independence, absorption by Russia or to stay part of Ukraine but with expanded power for the regions.

Surveys by polling companies have indicated that a significant majority of people in Ukraine reject movements to break away parts of the country.

Ukraine President Oleksandr Turchynov, in comments posted on the presidential website Saturday, said supporters of independence for the east "don't understand that this would be a complete destruction of the economy, social programs and general life for the majority of the population."

Turchynov and Ukraine's caretaker government came to power in February following the ouster of Russia-friendly President Viktor Yanukovych after months of protests in Kiev.

Moscow and many in Ukraine's east denounce the new government as a nationalist junta and allege that it intends to trample on the rights of eastern Ukraine's Russian-speakers.

More than 30 people have been reported killed since Ukrainian forces began mounting offensives to retake some eastern cities now under control of the insurgents.

Turchynov's chief of staff, Serhiy Pashynskyi, pledged Sunday that the government would seek to avoid further civilian casualties. "We will not engage in street fights in Slovyansk or elsewhere because that will lead to dozens of unnecessary deaths," he told reporters.

Late Saturday, State Department spokesperson Jen Psaki condemned the referendums as "illegal under Ukrainian law and ... an attempt to create further division and disorder.

"If these referenda go forward, they will violate international law and the territorial integrity of Ukraine," Psaki continued. "The United States will not recognize the results of these illegal referenda."

Ukraine is scheduled to hold a presidential election on May 25 to replace Yanukovych, who was deposed in February after months of protests over his pro-Russia stance and failure to conclude an economic treaty with the European Union.

German Chancellor Angela Merkel said Saturday that Putin must send more "signals of de-escalation" to help calm the situation in Ukraine and make presidential elections there possible.

Merkel spoke Saturday after meeting French President Francois Hollande in her constituency in northeastern Germany. The two leaders stressed their view that the sovereignty referendum planned by pro-Russian insurgents is illegitimate.

Merkel said: "The Russian president must send more signals of de-escalation" so the presidential elections can go ahead.

Merkel said she would like to see a "national dialogue" in Ukraine start next week if possible, but didn't specify who should participate.

Fox News' Greg Palkot and The Associated Press contributed to this report.