Cuban authorities have arrested 17 people in connection with what they described as a network to recruit Cuban nationals to fight for Russia in Ukraine.

The head of criminal investigations for Cuba’s Interior Ministry, César Rodríguez, said late Thursday on state media that at least three of the 17 arrested are part of recruitment efforts inside the island country.

He did not identify the alleged members of the network but said they had previous criminal records. Some families started speaking up about the case on Friday, and at least one mother said that her son was promised a job in construction in Russia.

Cuba’s Foreign Ministry said on Monday that the government had detected a network operating from Russia to recruit Cuban citizens living both in Russia and in Cuba to fight in Ukraine. It said authorities were working “to neutralize and dismantle” the network but gave no details.

“Cuba is not part of the war in Ukraine,” the Foreign Ministry said in a news release.

Cuba and Russia are political allies and Cubans do not require a visa to travel to Russia. Many go there to study or to work.

In May 2023, a newspaper in the Russian region of Ryazan, about 100 miles (62 kilometers) southeast of Moscow, reported from a military enlistment office there that “several citizens of the Cuba Republic” signed up to join the army. The Ryazanskiye Vedomosti newspaper quoted some Cubans as saying they were there to help Russia “complete tasks in the special military operation zone.” It also said “some of them in the future would like to become Russian citizens.”

In Havana, prosecutor José Luis Reyes told state TV that suspects are being investigated for crimes, including being a mercenary or recruiting mercenaries, and could face sentences of up to 30 years or life in prison, or even the death penalty.

Marilin Vinent, 60, said Friday that her son Dannys Castillo, 27, is one of the Cubans recruited in Russia.

At her home in Havana, she said her son and other Cubans traveled at the end of July to Russia after being promised work in a construction job. “They were all deceived,” she said.

Vinent showed reporters photos of her son in her cellphone, including some of him dressed in military fatigues.

She said that her son told her he had accepted the offer to go to Russia because he wanted to economically help the family, as the island is suffering an economic crisis, with people facing shortages of some products.

“I don’t know if my son is alive. We don’t know anything,” she said. “What I would like is to talk to him.”

The U.S. State Department said in a statement that it’s aware of the reports. “We are deeply concerned that young Cubans may have been deceived and recruited to fight for Russia in its brutal full-scale invasion of Ukraine, and we continue to monitor this situation closely,” it said.

Russian law allows foreign nationals to enlist in its army, after signing a contract with the Defense Ministry.

Since September 2022, foreigners who have served in the Russian army for at least one year are allowed to apply for Russian citizenship in a simplified procedure, without obtaining a residency permit first.

Moscow Mayor Sergei Sobyanin said earlier in September that the city was setting up “infrastructure to assist the Russian Defense Ministry in facilitating the enlistment of foreign nationals” in the capital’s main government office for migrants.

Last month, Russian media reported cases of authorities refusing to accept citizenship applications from Tajik nationals until they sign a contract with the Defense Ministry and enlist in the army. And in an online statement last week, the British Defense Ministry said there are “at least six million migrants from Central Asia in Russia, which the Kremlin likely sees as potential recruits.”

On X, a social media platform previously known as Twitter, the ministry said that “exploiting foreign nationals allows the Kremlin to acquire additional personnel for its war effort in the face of mounting casualties.”

It also noted that there have been online adds seeking recruits for the Russian army in Armenia and Kazakhstan.