MARIUPOL, Ukraine — Just an hour’s drive from this city under siege, at an old resort on the Azov Sea that’s now a military base, militants from Chechnya—veterans of the jihad in their own lands and, more recently, in Syria—now serve in what’s called the Sheikh Mansur Battalion. Some of them say they have trained, at least, in the Middle East with fighters for the so-called Islamic State, or ISIS.

Among the irregular forces who’ve enlisted in the fight against the Russian-backed separatists in the Donbas region of eastern Ukraine, few are more controversial or more dangerous to the credibility of the cause they say they want to serve. Russian President Vladimir Putin would love to portray the fighters he supports as crusaders against wild-eyed jihadists rather than the government in Ukraine that wants to integrate the country more closely with Western Europe.

Yet many Ukrainian patriots, desperate to gain an edge in the fight against the Russian-backed forces, are willing to accept the Chechen militants on their side.

Over the past year, dozens of Chechen fighters have come across Ukraine’s border, some legally, some illegally, and connected in Donbas with the Right Sector, a far-right-wing militia. The two groups, with two battalions, have little in common, but they share an enemy and they share this base.

The Daily Beast spoke with the Chechen militants about their possible support for the Islamic State and its affiliate in the Northern Caucasus region of Russia, which is now called the Islamic State Caucasus Emirate and is labeled a terrorist organization by both Russia and the United States.

The Chechen fighters said they were motivated by a chance to fight in Ukraine against the Russians, whom they called “occupiers of our country, Ichkeriya,” another term for Chechnya.

Indeed, they were upset that Ukrainian authorities did not allow more Chechen militants to move to Ukraine from the Middle East and the mountains of the Caucasus. The Sheikh Mansur Battalion, founded in Ukraine in October 2014, “needs re-enforcement,” they said.

The man the Chechens defer to as their “emir,” or leader, is called “Muslim,” a common forename in the Caucasus. He talked about how he personally crossed the Ukrainian border last year: “It took me two days to walk across Ukraine’s border, and the Ukrainian border control shot at me,” he said. He lives on this military base here openly enough but is frustrated that more of his recruits can’t get through. “Three of our guys came here from Syria, 15 more are waiting in Turkey,” he told The Daily Beast. “They want to take my path, join our battalion here right now, but the Ukrainian border patrol is not letting them in.”

Muslim pulled out a piece of paper with a name of another Chechen heading to join the battalion. The handwritten note said that Amayev Khavadzhi was detained on September 4, 2014, in Greece and now could be deported to Russia. (Khayadzhi’s lawyer in Greece told The Daily Beast on the phone that there was a chance that his defendant would be transferred to his family in France instead.)

“Two more of our friends have been detained, and are threatened with deportation to Russia, where they get locked up for life or Kadyrov kills them,” Muslim told The Daily Beast, referring to the pro-Putin strongman of Chechnya, Ramzan Kadyrov.

The commander pointed at a young bearded militant next to him: “Mansur came here from Syria,” Muslim said. “He used ISIS as a training base to improve his fighting skills.” Mansur stretched out his right hand, which was disfigured, he said, by a bullet wound. Two more bullets were still stuck in his back, he said.

“No photographs,” Mansur shook his head when a journalist tried to take his picture. Not even of his hand, not even from the back: “My religion does not allow that.”

In fact, to demonstrate they were tough, armed, and that their numbers were growing these Chechens posted their photographs on the Russian social network Vkontakte, which actually is controlled by the Russian government. But several had their faces blanked out, presumably to avoid prosecution, whether in Russia or the West.

“Kadyrovtsy [Kadyrov] knows my face and my hand too well,” Mansur explained to The Daily Beast.

Mansur said he did not have to run across the border under a hail of of bullets like Muslim. “We managed to reach an agreement with the Ukrainians,” he said.

The arrival of pro-Ukrainian Chechen fighters from abroad helped relieve some of the immigration problems of Chechens already living in Ukraine, the militants explained.

Kadyrov had sent some of his Chechens to fight on the Russian side of the conflict last year, said Muslim, and as a result “there was a temporary danger that Chechen families might be deported from Ukraine… But as soon as we started coming here last August, no Chechen in Ukraine had reasons to complain.”

Were former fighters coming to Ukraine from Syria because they were disappointed (or appalled) by the ideology of ISIS?

“We have been fighting against Russia for over 400 years; today they [the Russians] blow up and burn our brothers alive, together with children, so here in Ukraine we continue to fight our war,” the commander said. Many in Ukraine remembered the Chechen war of the mid-1990s as a war for independence, which briefly was given, then taken away.

Since then the war in the Caucasus has morphed into terrorism, killing about 1,000 civilians, many of them children, in a series of terror attacks. And whatever the common enemy, that poses a serious problem for Kiev if it embraces such fighters.

“The Ukrainian government should be aware that Islamic radicals fight against democracy,” says Varvara Pakhomenko, an expert at the International Crisis Group. “Today they unite with Ukrainian nationalists against Russians, tomorrow they will be fighting against liberals.”

Pakhomenko says something similar happened in Georgia in 2012 when the government there found itself accused of cooperation with Islamic radicals from Europe, Chechnya, and the Pankisi Gorge, an ethnic Chechen region of Georgia.

For international observers covering terrorism in Russia and Caucasus in the past 15 years, the presence of Islamic radicals in Ukraine sounds “disastrous,” monitors from the International Crisis Group told The Daily Beast.

But many ordinary Ukrainians and officials in Mariupol support the idea of retaining more Chechen militia fighters. “They are fearless fighters, ready to die for us, we love them, anybody who would protect us from death,” said Galina Odnorog, a volunteer supplying equipment, water, food, and other items to battalions told The Daily Beast. The previous night Ukrainian forces reported six dead Ukrainian soldiers and over a dozen wounded.

“ISIS, terrorists—anybody is better than our lame leaders,” says local legislative council deputy Alexander Yaroshenko. “I feel more comfortable around Muslim and his guys than with our mayor or governor.”

The Right Sector battalion that cooperates with the Chechen militants is a law unto itself, often out of control, and tending to incorporate anyone it wants into its ranks. In July two people were killed and eight wounded in a gun and grenade battle between police and Right Sector militia in western Ukraine. On Monday, Right Sector militants triggered street battles in the center of Kiev that left three policemen dead and over 130 wounded.

Yet the government in Kiev has been considering the transfer of the Right Sector into a special unit of the SBU, Ukraine’s security service, which has made many people wonder whether the Chechen militia will be joining the government units as well. So far, neither the Right Sector battalion nor the Chechen battalion have been registered with official forces.

In Ukraine, which is losing dozens of soldiers and civilians every week, many things could spin out of control but “it would be unimaginable to allow former or current ISIS fighters to join any government-controlled or -sponsored military unit,” says Paul Quinn-Judge, senior adviser for International Crisis Group in Russia and Ukraine. “It would be politically disastrous for the Poroshenko administration: No Western government in its right mind would accept this, and it would be an enormous propaganda gift for the Kremlin. The Ukrainian government would be better served by publicizing their decisions to turn ISIS vets back at the border.”