Ukraine’s prime minister said he fears recent softer comments from Russian President Vladimir Putin are a prelude to provocation, as Kiev tightened security around celebrations Friday to mark the Soviet victory in World War II.

“I am concerned about the statement of Vladimir Putin. It caused a bad feeling. They say one thing and do another. After this statement, I asked law enforcement officers to strengthen security measures on May 9,” Arseniy Yatsenyuk told Ukrainian television.

On Wednesday, the Kremlin strongman stunned the world with an abrupt u-turn on Ukraine, calling on pro-Russian separatists in the east to delay independence referendums planned for this weekend and welcoming a May 25 presidential election.

But the rebels holed up in more than a dozen towns and cities in eastern Ukraine defied his plea and vowed to press ahead with referendums this Sunday that are bound to stoke tensions.

In contrast to the display of patriotic fervour and military hardware on Red Square, Ukraine is planning muted “Victory Day” celebrations in a bid to avoid violence.

The head of Kiev’s city council has banned large-scale public gatherings or parade in the capital, fearing that the veterans could be attacked by Russian provocateurs.

Ukraine’s interim president Oleksandr Turchynov has told people in all parts of the country to be on full alert amid fears of pro-Russian provocation.

“Roadblocks have been set up around our capital, where serious checks are being carried out, because we expect that provocative actions may occur on May 9,” Turchynov told Ukrainian television on Monday.

“Not just in the capital. It is necessary to stay alert in all regions of our country. There may be saboteurs. There may be provocateurs. War is in effect being waged against us and we must be ready to repel this aggression,” he added.

Victory Day is Russia’s most important secular holiday and a key element of the national identity, reflecting the nation’s enormous suffering and honoring millions of victims of World War II.

The holiday also offers a chance to display the nation’s massive military arsenal.

About 11,000 troops proudly marched across Red Square to the tunes of marches and patriotic songs. Some 150 military vehicles and about 70 combat aircraft took part in the show.