Ukrainian internal soldiers take part in a training at a military base in Donetsk on March 29. (Alexander Khudoteply/AFP/Getty Images)

Some people are making sure their cars stay gassed up, in case their families need to flee advancing tanks. Others are stockpiling food so they can dig in if there is an invasion. A few talk about learning to shoot. Nearly everyone is worried.

Tens of thousands of Russian soldiers are massed along the Ukrainian border, U.S. officials report, with large contingents gathered near the Donetsk region in eastern Ukraine. Russian officials say the troops are conducting routine exercises. On Saturday, Russian Foreign Minister Sergei Lavrov said Moscow has no intention of using them against Ukraine.

But ever since Russian President Vladimir Putin annexed Ukraine’s Crimean Peninsula after a hastily arranged referendum March 16, few here know what to believe. This is a Russian-speaking region that has long been well disposed toward its neighbor. Some small but vocal groups, fearing that they will get short shrift from Kiev, have demonstrated against the Ukrainian government. There have been demands for a referendum on joining Russia. But no one is asking for war.

“I worry about it all the time,” said Anatoly Akimochkin, first vice chairman of the Independent Trade Union of Miners of Ukraine. “Any kind of intervention will mean war, and the border is not far away. Some are ready to take up arms and defend their state. And there are some who would welcome Russian troops.”

Russian television channels are widely watched here, he said, and they have assaulted Ukrainians with propaganda, describing Kiev as being in the hands of fascists on their way to kill eastern Ukrainians. People are being brainwashed, he said, which accounted for the pro-Russian demonstrations, although lately those have been diminishing.

A confectionary billionaire and a former Ukrainian Prime Minister are going head to head in the country's May elections. (Reuters)

Perhaps 500 people gathered Saturday around the statue of Vladimir Lenin in the city of Donetsk, waving a few Russian flags in the bitter-cold wind, shouting for protection of the Russian language and denouncing Kiev as an illegitimate government. A small contingent of policemen stood by, trying to keep warm. Few people were on the streets.

“I am really afraid Russia will invade us,” said Aleksey Ryabchyn, a 30-year-old husband and father and a second lieutenant in the army reserve, as he chatted in a cafe. “Putin doesn’t follow logic — no one expected him to annex Crimea. I don’t think the U.S. will fight for us. We are on our own.”

Ryabchyn, the son of a Russian mother and a Ukrainian father, came of age after the fall of the Soviet Union and has always regarded Russia and Ukraine as separate but close, like the United States and Canada.

Now some of his friends are keeping their gas tanks filled, fearing they’ll have to drive their families to safety in western Ukraine at any moment. Others talk about partisan warfare.

“These are the most critical days of our independence,” Yevhen Marchuk, a former Ukrainian defense minister, said in Kiev. The Russian soldiers will have to invade soon, he said, or return to their barracks.

“It’s impossible for an army to stay there for long,” he said. “There are all the signs that a military attack could happen. It doesn’t mean it’s inevitable.”

Kateryna Zhemchuzhnykova, a 25-year-old journalist, tries to keep her mind on her work to avoid thinking about what could happen. She lives with her parents, who are filling the larder with food to see them through a possible invasion.

The Donetsk governor, billionaire businessman Serhiy Taruta, has used his own money to have a trench dug, more than 12 feet wide and eight feet deep, along the coal-mining region’s 90-mile border with Russia in an effort to ward off invasion.

Taruta was appointed to the office by the new government in Kiev, which took over after President Viktor Yanukovych fled the country Feb. 22 following months of protests in favor of good government and closer ties with Europe rather than Russia.

He was not especially cheered by the news that Putin had called President Obama on Friday to suggest that a diplomatic solution to the Ukrainian crisis was possible. There have been a lot of phone calls, Taruta said, that have resulted in nothing.

“It’s important to understand that America needs not only to hold negotiations but to provide guarantees to Ukraine of territorial integrity,” he said. “We have the impression the West is more interested in the economic situation than in democracy. The Ukrainian people feel betrayed.”

He was referring to the 1994 Budapest Memorandum, in which the United States persuaded Ukraine to give up its nuclear weapons in return for a guarantee of protection from Britain, the United States and, ironically, Russia. In business, Taruta said, when you sign an agreement, you follow through.

“Everyone’s afraid,” said Oleksiy Matsuka, who writes for an independent online newspaper, “especially businessmen, those who have something to lose. If Russia took over, there would be a partisan war. Everyone would suffer.”

Pro-Russians are not calling for an invasion. Kirill Cherkashin, a sociologist, said the differences between Ukraine’s east and west are so deep that the east would be better off going its own way and joining Russia. There’s a danger, he said, that if the west subjugates the east, a partisan war could erupt, but that should be avoided.

“The best way out is a peaceful option,” Cherkashin said, “like in Czechoslovakia.”