KYIV/VIENNA, Sept 6 (Reuters) - Ukrainian officials said they would announce on Tuesday a major new military success in the east of the country, an unexpected advance just a week after Kyiv declared a big new counter-offensive hundreds of kilometres away in the south.
"Tonight there is going to be great news from President Zelenskiy on (the) counteroffensive operation in Kharkiv region," Zelenskiy advisor Serhiy Leshchenko said on Twitter, referring to the northeastern province around Ukraine's second biggest city.
Though Ukrainian officials did not give specific details, several posts on social media from military bloggers and witnesses reported fighting around Balakliia, a town of 27,000 people that lies between Kharkiv and Russian-held Izyum, a city with a major railway hub used by Moscow to supply its forces.
Reuters was not able to independently verify those reports.
Gaining control of Balakliia could facilitate a Ukrainian attempt to encircle or partially encircle Izyum, said Kyiv-based military analyst Oleh Zhdanov.
Little information has emerged about progress of the main Ukrainian offensive in the southern Kherson region, with Kyiv barring journalists from the front line and releasing only limited reports to preserve the element of surprise.
Russia says it has repelled the Kherson assault, but Ukraine has reported steady success, including releasing pictures on Sunday of troops hoisting a flag over a rooftop in a newly captured town.
Western military experts say Ukraine's aim in the south appears to be to trap thousands of Russian troops on the west bank of the wide Dnipro River and cut them off by destroying their rear supply lines.
The announcement of a simultaneous Ukrainian advance near Kharkiv was an indication that Russian forces were now having difficulties reinforcing along the huge length of the front, said Mark Hertling, a retired former U.S. commander of ground forces in Europe.
"This confirms RU inability to maneuver forces between theater locations & within their force's defensive 'stance' to counter Ukrainian offensive actions," Hertling tweeted. "RU is nursing wounds, bearing loss of combat capabilities (people & equipment), have bad leaders."
There have also been increasing attacks by Ukrainians in Russian-occupied areas against Moscow-installed authorities.
On Tuesday, the Russian-installed commandant of Berdiansk, a port in the south, was badly injured when his car was blown up outside the city administration building, pro-Russian local officials said, blaming Kyiv for the attack on Artyom Bardin.
The New York Times quoted U.S. officials saying Russia, running low on supplies, was resorting to buying artillery shells from North Korea. Moscow did not comment on the report.
IAEA CALLS FOR HALT TO FIGHTING NEAR PLANT
The International Atomic Energy Agency (IAEA) called on Tuesday for fighting to be halted in a security zone around Europe's biggest nuclear power station, located in Russian-controlled territory along the front.
A long-awaited report did not ascribe blame for damage to the Zaporozhzhia nuclear power plant, which Russia and Ukraine each accuse the other of shelling. But it called the situation unsustainable and said unless the shooting stops there would be a risk of disaster.
The plant, seized by Russia shortly after its invasion, is controlled by Russian forces but run by Ukrainian technicians. It sits on a Russian-held bank of a huge reservoir, opposite Ukrainian positions across the water.
"While the ongoing shelling has not yet triggered a nuclear emergency, it continues to represent a constant threat to nuclear safety and security with potential impact on critical safety functions that may lead to radiological consequences with great safety significance," the IAEA wrote.
"The IAEA recommends that shelling on site and in its vicinity should be stopped immediately to avoid any further damages to the plant and associated facilities," it said. "This requires agreement by all relevant parties to the establishment of a nuclear safety and security protection zone."
Inspectors said they had found Russian troops and equipment at the plant, including military vehicles parked in turbine halls. Moscow has denied accusations that it used the plant as a shield for its forces, but says it has troops guarding it.
"Ukrainian staff operating the plant under Russian military occupation are under constant high stress and pressure, especially with the limited staff available," the IAEA report said. "This is not sustainable and could lead to increased human error with implications for nuclear safety."
IAEA inspectors led by the agency's chief, Rafael Grossi, braved shelling to cross the front line and reach the power station last week. Two experts have stayed on to maintain a long-term presence.
Earlier on Tuesday, blasts rang out and power was cut in the city surrounding the plant, Enerhodar, according to Dmytro Orlov, the Ukrainian mayor who operates from outside Russian-held territory. Moscow repeated its longstanding accusations that Ukrainian forces had been shelling the plant.
Kyiv accuses Russia of staging such incidents, to undermine international support for Ukraine and as a possible pretext to cut the plant from the Ukrainian power grid and steal its output. Russia has so far spurned international pleas to pull its forces back from the site and demilitarise the area.
The IAEA report listed areas of the plant that had been damaged, including a building housing nuclear fuel, a facility for storing radioactive waste, and a building housing an alarm system. It said the power station had been cut off several times from offsite power supplies critical to its safe operation.
