The self-defense forces of the self-proclaimed Donetsk People’s Republic (DPR) have left the cities of Slavyansk and Kramatorsk and are heading to the south of the region, according to the republic’s headquarters.

A column of DNR militia arrived from Slavyansk - which had been surrounded by the Kiev military - to Kramatorsk on Saturday night. However, the self-defense forces later left Kramatorsk as well and are now heading towards areas in the Donetsk region – such as the city of Gorlovka - which remain under militia control.

“Kramatorsk was difficult to defend because of its poor location. That’s why the Command decided to leave the city,” a representative of the DPR headquarters told RIA Novosti agency.

However, the source stated, small self-defense groups remain both in Slavyansk and Kramatorsk ready to fight with the Kiev forces.

BREAKING: #Ukraine government armoured now rolling into #Kramatorsk, according to @Ruptly stringer on the ground. — Ruptly Newsroom (@RuptlyNewsroom) July 5, 2014

Meanwhile, Ukrainian Prime Minister Arseny Yatsenyuk has announced that the military operation on “liberating Slavyansk and Kramatorsk from terrorists” has been accomplished, the government press-service reported on Saturday.

The country’s President Petro Poroshenko called the “liberation of Slavyansk” symbolic.

“It’s not a complete victory yet. But the clearing of Slavyansk from an armed to teeth gang of bigots has a huge symbolic meaning,” he said Saturday commenting on the issue, his official website reports. According to Poroshenko, it is a turning point “in the fight with terrorists for the territorial integrity of Ukraine” and for “the return to normal life” in the Donetsk region.

Poroshenko ordered authorities to provide humanitarian aid to residents of Slavyansk and other areas “liberated from militants”. He also promised that works to resume water and energy supply will start in the nearest future.

So far though, the military operation seems to have brought local residents only grief and devastation.

“You think you won? That was a tactical retreat. We will enter Slavyansk again, with victory,” Denis Pushilin, one of the DPR leaders twitted.

Slavyansk residents say government forces are checking locals’ IDs and detaining all suspicions individuals.

As Russian Channel One reported earlier, the self-defense forces have been forced to leave Slavyansk after a “massive shelling” of the city following which armored vehicles entered the area and street fighting began. That’s when the self-defense forces took the decision to leave the city, the channel said.

“Despite the massive shooting, the fighters stormed out of the city and headed for neighboring Kramatorsk. Part of their hardware was shot down in the process,” the channel said.

Ukrainian President Petro Poroshenko ordered the military to raise the Ukrainian flag over Slavyansk, his press service said.

“The head of General Headquarters Viktor Muzhenko has reported to Ukraine’s president, Petro Poroshenko, about the fact that overnight, while the self-defense groups were trying to escape Slavyansk they came under mortar fire from the Ukrainian military. As a result, one armored vehicle, two infantry fighting vehicles and two airborne combat vehicles belonging to the [self-defense] fighters have been shot down,” the press service also said.

Hours later as self-defense troops left their second stronghold as well, the Ukrainian flag was raised over the Kramatorsk administration building, which was used as the DPR headquarters.

“In the early afternoon all the DNR soldiers came to Kramatorsk from Slavyansk. They all massed in the Lenin square and around the center,” American photographer Patrick Lancaster told RT by phone adding that two hours later the self defense forces left the city.

Preparing to leave the city, the self-defense fighters distributed food and water supplies from DNR amongst the local population, Lancaster says, adding that they had also taken down DNR posters and insignia, that included the flag of the self proclaimed republic.

“When the Ukrainian army entered the main square, there were around two tanks, two APCs, and 15-20 foot soldiers, some of them snipers and some carrying rocket-propelled grenades,” Lancaster recalls.

They went on to fly the Ukrainian bi-color flag on the roof of the former DNR headquarters. After parading the flag around, “they jumped back on their tanks, and left,” Lancaster says.

The Slavyansk militia relocated to the capital of the region Donetsk and the surrounding area with eyewitnesses reporting a lot of DPR’s military hardware and “suntanned and bearded men with tattoos,” RIA Novosti quotes.

After the militia were forced to leave their positions in the northern part of the front, they moved to reserve positions that had been prepared in advance, Itar-Tass news agency reported, citing Prime Minister of the Donetsk People’s Republic, Aleksandr Boroday, as saying.

“Our troops have consolidated at the reserve lines of defense, in an organized way and having kept their weaponry. We were prepared for this option, as we have to face tens of thousands of Kiev's military men and hundreds of armored weaponry units – which means almost all the battle-ready Ukrainian army,” Boroday said.

"Taking into account the ‘scorched earth’ tactics employed by Kiev's punitive forces, and the strategy of genocide toward the Donbass population, we declare that every hour of military action claims civilians’ lives,” Boroday said.

In connection with this, he appealed to the international community, calling on them to “influence the Ukrainian authorities and stop the killings of civilians.

Loud explosions were heard in the area of the Donetsk airport, and gunfire is going on there, local residents told RIA-Novosti news agency. Also, two fighter jets were spotted carrying out strikes on unidentified targets in the area where the airport is situated.

“We are asking the people living near the airport not to leave their apartments, to stay away from their windows and not to go outside except in case of urgent necessity,” the website of the Donetsk mayor’s office said in a warning.

READ MORE: Kiev's bloody eastern Ukraine campaign LIVE UPDATES

The Russian Foreign Ministry announced Saturday that Moscow is halting the process of delivering weapons, Ukrainian military forces' equipment and funds from the territory of Crimea to Kiev authorities due to their military actions in the east, which have resulted in the “deaths of civilians, including children, and civilian infrastructure in Donetsk and Lugansk regions being destroyed.”

“The decision will be valid until a full ceasefire in the east of Ukraine by the country’s military and until a peaceful solution is reached,” Russia’s Foreign Ministry said.

Kiev to detect ‘traitors’ among police in Donetsk region

Ukrainian Interior Ministry has announced it is going to launch an investigation against “every policeman” in Slavyansk to find out whether they cooperated with the self-defense forces.

Such line-of-duty checks will define if “an employee of Slavyansk police cooperated with separatists or maintained loyalty to the Ukrainian people,” Deputy Interior Minister Sergey Yarovoy said, as cited by Ukrainian media.

Police in the Donetsk region will be reformed - starting from the cities of Donetsk and Lugansk “due to necessity” - said Interior Minister Arsen Avakov. And for now, law enforcers from other Ukrainian regions will be sent to work in the area.

“Policemen from the entire country will be working there, including those who got though the filter of fighting during the anti-terrorist operation – in other words guys who were not afraid,” he told journalists, as sited by segodnya.ua news portal.

All the policemen who violated their oaths and left their guard posts in Donetsk and Lugansk region have been fired, Avakov said. He added that in some cases, “these people were arrested”.