People gather in Kyiv to look at destroyed Russian military equipment.
CNN  — 

Events to mark Ukraine’s Independence Day on Wednesday have been banned in the country’s capital, Kyiv, and second-largest city, Kharkiv, as Ukrainian President Volodymyr Zelensky and other officials warn that Russia may carry out missile strikes.

Zelensky said on Saturday that Russia might be planning “particularly ugly” attacks to coincide with the occasion, which will mark 31 years since Ukraine broke its ties with the Soviet Union and as the war nears its six-month milestone.

“We must all be aware that this week Russia could try to do something particularly ugly, something particularly vicious,” Zelensky said in a video message.

“One of the key tasks of the enemy is to humiliate us, Ukrainians, to devalue our capabilities, our heroes, to spread despair, fear, to spread conflicts … Therefore, it is important never, for a single moment, to give in to this enemy pressure, not to wind oneself up, not to show weakness,” he said.

In Kyiv, the city military administration issued a ban on all big gatherings between Monday and Thursday, saying “it is forbidden to hold mass events, peaceful meetings, rallies and other events related to a large gathering of people.”

General Mykola Zhyrnov, head of Kyiv’s military administration, said that the order was imposed so that security forces could respond in a “timely manner to threats of missile and bomb attacks by the troops of the Russian Federation on decision-making centers, military facilities, defense industry facilities, critical infrastructure and nearby residential areas.”

Zhyrnov said he had ordered city authorities to use the minimum necessary number of officials, civil servants and workers to ensure transport and other services.

In Kharkiv, where relentless, indiscriminate Russian attacks killed and injured hundreds of civilians in the first months of the war, authorities announced a curfew from 7 p.m. local time on the eve of Independence Day to 7 a.m. on the day after.

“We ask that you understand such measures and prepare to stay at home and in shelters – this is our safety,” authorities said.

Natalia Humeniuk, a spokesperson for Ukraine’s southern military command, said Sunday that “the date of our independence and the anniversary of the invasion, half a year, coincide – it is the 24th. And there’s Ukrainian flag day, on the 23rd. We are ready for the fact that there will be an increase in some kind of aggression, there will be an increase in missile attacks.”

In the last week, Ukrainian officials have said that more Russian missiles have been deployed at an airbase in Belarus. Artillery shells also continue to rain down near Europe’s biggest nuclear plant in southern Ukraine.

Meanwhile, media personalities in Moscow on Monday called for strikes on Kyiv in response to the murder of Darya Dugina, a Russian political commentator and the daughter of influential ultranationalist Alexander Dugin.

Russia’s Federal Security Service (FSB) blamed an agent with the Ukrainian security service for the car bomb explosion that killed Dugina on Saturday, Russian state news agency TASS reported, triggering the calls for attacks in the capital and elsewhere.

CNN cannot independently verify the FSB claims cited by the TASS report. Ukraine has denied any involvement in the death of Dugina.