Far from their homes in one of the world’s most isolated and secretive states, about 11,000 North Korean soldiers find themselves at the center of Europe’s biggest conflict since World War II.

Little is known about the North Korean troops deployed to support Russia in its devastating yearslong war in Ukraine — or what exactly they will be ordered to do — and their presence hasn’t even been officially acknowledged by Moscow or Pyongyang.

US, Ukrainian and South Korean intelligence says the North Koreans have already engaged in combat operations, joining a Russian force of tens of thousands to carry out an assault on Ukrainian positions in Russia’s western Kursk region. Speculation has been rife about how these troops will fare.

North Korea has seen “several hundred” casualties — both killed and wounded — in the Kursk region since sending thousands of forces to Russia in October, a senior US official said Tuesday.

According to Ukraine, at least 30 North Korean soldiers were killed or wounded in fighting over the weekend alone near villages in Kursk close to the Ukrainian border. One Ukrainian unit reported that North Koreans — wearing different uniforms from the Russians — had launched infantry attacks using the “same tactics as 70 years ago,” in an apparent reference to the Korean War, where waves of infantry were used.

On Thursday, a South Korean lawmaker said about 100 North Korean soldiers are believed to have been killed and almost 1,000 injured since being deployed to Kursk, according to the country’s intelligence agency.

Lee Seong-kwon, who was briefed by the National Intelligence Service, said the agency had seen signs that the casualties include “general-level officials.”

Pyongyang’s soldiers lack real-world battle experience and will face unfamiliar terrain in a brutal, modern war theater – one that has wrought chaos and horror for both sides as the dead pile up across the front lines.

“If I was going to describe their capability more broadly and not think about the kit that they had, I would tell you that these are not battle-hardened troops, they haven’t been in combat before,” the US official said, adding their assessment was that casualties included “all ranks” including leaders at command-and-control nodes.

But some analysts have warned against underestimating the North Koreans.

North Korean leader Kim Jong Un will be sending “the best” from an elite force of highly trained and “indoctrinated” soldiers known as the Storm Corps, according to retired Lt. Gen. Chun In-bum, a veteran of the South Korean army.

Some are special forces, like the US Navy Seals or Rangers, or Britain’s SAS. Others are light infantry and snipers, he said.

The Storm Corps — the 11th Army Corps of the North Korean military — are “better trained, (have) better physique and (are) better motivated than your average North Korean soldier,” Chun said.

North Korean propaganda material released by state media this year has shown Kim overseeing special operations training marked by extreme displays of strength, including the smashing of cinder blocks over the ripped torsos of soldiers stripped to the waist.

Michael Madden, a non-resident fellow in the 38 North program at the Stimson Center in Washington, said this largest deployment of North Korean soldiers since the Vietnam War is equipped with “certain psychological tricks” to persevere.

“These guys are programmed. These guys are indoctrinated,” he said. “But the question is, how well indoctrinated? How well programmed are they?”

“They are probably better positioned than other members of the military, or other members of militaries going into a foreign conflict, in terms of the preparation of their minds.”