KYIV, Ukraine (AP) — Russian President Vladimir Putin doubled down Wednesday on his faltering invasion by declaring martial law in four illegally annexed Ukrainian regions and setting the stage for draconian new restrictions and crackdowns throughout Russia. The drastic escalation appeared to be prompted by the threat of more stinging battlefield defeats, sabotage and troubles with his troop mobilization.

The order belies the Kremlin’s attempts to portray life in the annexed regions as returning to normal, with the latest example the removal of civilian leaders, the installation of a military administration and a mass evacuation in Kherson.

With a Ukrainian counteroffensive grinding toward Kherson, the battle for the annexed southern city of more than 250,000 people, key industries and a major port is a pivotal moment for Ukraine and Russia heading into winter, when front lines could become largely frozen for months.

In announcing martial law, effective Thursday, Putin told his Security Council, “We are working to solve very difficult large-scale tasks to ensure Russia’s security and safe future.”

It was Putin’s latest attempt to solidify control of not only the annexed regions but his entire country as he faces threats not only from the largely successful Ukrainian counteroffensive, but sabotage of a strategically important bridge linking Russia with Crimea, assassinations of Kremlin-installed officials in Kherson and chaos and mistakes in his partial troop mobilization.

Putin’s martial law declaration authorized creation of territorial defense forces in the annexed regions of Kherson, Donetsk, Luhansk and Zaporizhzhia, along with the potential impositions of curfews, restrictions on travel and public gatherings, tighter censorship and broader law enforcement powers.

In a potentially ominous move, Putin’s order opens the door for restrictive measures to be extended across Russia. That may lead to an even tougher crackdown on dissent and freedom in Russia, where authorities have dispersed antiwar protests and jailed people for making statements or providing information about the fighting that differs from the official line.

The severity of restrictions inside Russia depends on proximity to Ukraine, covering freedom of movement and other security steps.

In the Kherson region, Ukrainian forces have pushed back Russian positions on the west bank of the Dnieper River. By pulling civilians out and fortifying positions in the region’s main city, which backs onto the river, Russian forces appear to be hoping that the wide, deep waters will serve as natural barrier against the Ukrainian advance.

A trickle of evacuations from the city in recent days has become a flood. Local officials said Wednesday that 5,000 had left the city already out of an expected 60,000. Russian state television showed residents crowding on the Dnieper’s banks, many with small children, to cross by boats to the east — and, from there, deeper into Russian-controlled territory.

Russia has said the movement of Ukrainians to Russia or Russian-controlled territory is voluntary, but in many cases, they have no other routes out, and no other choice. Under martial law, authorities can force evacuations.

Reports have circulated of forced deportations, and an Associated Press investigation found that Russian officials deported thousands of Ukrainian children to be raised as Russian.

Russian authorities played up fears of an attack on Kherson, seemingly to persuade residents to leave. Text messages warned residents to expect shelling, Russian state media reported.

One resident reached by phone described military vehicles leaving the city, Moscow-installed authorities scrambling to load documents onto trucks, and thousands of people lining up for ferries and buses.

“It looks more like a panic rather than an organized evacuation. People are buying the last remaining groceries in grocery shops and are running to the Kherson river port, where thousands of people are already waiting,” the resident, Konstantin, said. The AP is withholding his family name, as he requested, for his safety.

“People are scared by talk of explosions, missiles and a possible blockade of the city,” he added.

Leaflets told evacuees they could take two large suitcases, medicine and food for a few days.

Andriy Yermak, head of the Ukrainian presidential office, called the evacuation “a propaganda show” and said Russia’s claims that Kyiv’s forces might shell Kherson were “a rather primitive tactic, given that the armed fdo not fire at Ukrainian cities.”

Ukrainian military analyst Oleh Zhdanov said the operation could presage intense fighting and “the harshest” tactics from Russia’s new commander for Ukraine, Gen. Sergei Surovikin.

“They are prepared to wipe the city from the face of the Earth but not give it back to the Ukrainians,” Zhdanov said in an interview.

In a rare acknowledgement of the pressure that Kyiv’s troops are exerting, Surovikin himself described the situation his forces face in the Kherson region as “very difficult.” Russian bloggers interpreted the comments as a warning of a possible Kremlin pullback. Surovikin claimed that Ukrainian forces were planning to destroy a hydroelectric facility, which local officials said would flood part of Kherson.

Incapable of holding all the territory it has seized and struggling with manpower and equipment losses, Russia has stepped up air bombardments, with a scorched-earth campaign targeting Ukrainian power plants and other key infrastructure. Russia has also increased its use of weaponized Iranian drones to hit apartment buildings and other civilian targets. In the invasion’s opening stages in February, Russian commanders had seemingly sought to spare some utilities they might need.

Russia launched numerous missiles over Ukraine on Wednesday. Ukrainian authorities said they shot down four cruise missiles and 10 Iranian drones. Energy facilities were hit in Vinnytsia and Ivano-Frankivsk.

Air raid sirens blared in the Ukrainain capital, Kyiv, sending many people into metro stations for shelter. Mayor Vitali Klitschko announced the city would start seasonal centralized heating on Thursday at lower temperatures than normal to conserve energy.

Ukrainian President Volodymyr Zelenskyy reported Tuesday that nearly a third of the country’s power stations had been destroyed since Oct. 10, causing blackouts. One area where power and water were reported knocked out due to overnight shelling was Enerhodar. The southern city is next to the Zaporizhzhia nuclear power plant, which is one of the war’s most worrisome flashpoints.

Missiles severely damaged an energy facility near Zelenskyy’s hometown, Kryvyi Rih, a city in south-central Ukraine, cutting power to villages, towns and to one city district, the regional governor reported.

In Chernihiv city, Iranian drones left three people wounded, said Regional Gov. Viacheslav Chaus.

Karmanau reported from Tallinn, Estonia.