A pro-Russian fighter mans a checkpoint in the eastern Ukrainian city of Donetsk on July 7, 2014. Pro-Russian rebels erected new barricades on the streets of Donetsk on Monday, preparing to make a stand in the city of a million people after losing their bastion in the town of Slaviansk in the worst defeat of their three month uprising. Reuters/Maxim Zmeyev

After retreating from Slavyansk, eastern separatists in Ukraine are barricading the city of Donetsk in expectation of a battle with the Ukrainian military.

Mykhaylo Koval, a Ukrainian security official, said the military plans to “completely blockade” both Donetsk and Luhansk, two epicenters of separatist sentiments in eastern Ukraine. Donetsk is home to a million people and the capital of the self-proclaimed “Donetsk People’s Republic,” one of the main eastern separatist states.

Koval said the blockade will be followed by “corresponding measures that will force the separatists, the bandits to lay down their arms.”

Three bridges were blown up on roads leading to Donetsk. Separatist leaders did not take responsibility for blowing up the bridges and blamed it on pro-government saboteurs. One railway bridge was blown up over a major highway from government-held Slavyansk and Donetsk outside the village of Novobakhmutivka, leaving a train precariously hanging over the road.

A man holding an umbrella walks past a destroyed railroad bridge which fell over a main road leading to the eastern Ukrainian city of Donetsk, near the village of Novobakhmutivka, north of Donetsk July 7, 2014. Ukraine's richest man pleaded with the government on Monday not to bomb Donetsk, a city of a million people where hundreds of heavily armed pro-Russian rebels have vowed to make a stand after losing control of their bastion in the town of Slaviansk. REUTERS/Maxim Zmeyev

Ukraine’s richest man, Rinat Akhmetov, who has largely stayed out of the conflict except to periodically appeal for negotiations, reportedly pleaded with the military on Ukrainian TV to spare Donetsk, his hometown.

“Donetsk must not be bombed. Donbass must not be bombed,” Akhmetov said. “Cities, towns and infrastructure must not be destroyed. Most importantly, we must avoid suffering and deaths of peaceful people. Donetsk is the capital of Donbass and Donbass is a symbol of labor. It is home to strong, hardworking and good people; proud, brave and warm-hearted people. But most importantly, they are peaceful people.”

Thousands of residents of Donetsk echo Akhmetov’s concerns and have fled the city. Businesses have shut down or moved operations out of the city. The Guardian reported that ATMs have run out of cash, shops shut early and that it is not uncommon to see men with machine guns outside a restaurant or driving an ambulance.

Denis Pushilin, a separatist leader remained defiant as he claimed victory in a nearby fight with the Ukrainian military and vowed to “take Kiev," but that declaration may not have much weight if local reports saying he has left Ukraine for Russia are true. However, Pushilin seems to have the support of other Donetsk residents who chose to stay and support the rebels.

About a thousand people gathered on Monday to rally around the rebels and protest Ukrainian military action in the east, according to reports, while rebels, reportedly in good spirits, commandeered a World War Two-era tank from a local museum to outfit it for use against government forces.