Nearly three dozen Cuban asylum seekers were confined to the Leeward side of the U.S. Navy base at Guantánamo Tuesday, no longer able to send packages to family across the minefield in a security crackdown at the U.S. migrant center at the base in southeast Cuba.

Officials wouldn’t say precisely how the Cubans lost privileges of wider access on the base. But “several of the migrants repeatedly broke Naval Station rules in place to ensure base security,” said Deborah Sisbarro at the State Department’s Bureau of Population, Refugees and Migration.

The infractions occurred “in the last several weeks,” she said.

The Miami Herald was first alerted to a problem by a pro-Cuban government blogger in Havana, who posted from the Cuban government-controlled side of the island that 10 Cuban migrants were on a hunger strike. But Sisbarro said Tuesday that the hunger strike was short-lived, Feb 2-4.

As of Tuesday, the base was housing 33 Cubans, ages 18 to 53, who were picked up at sea by the U.S. Coast Guard and found to be potential candidates for asylum anywhere but the U.S.

The “migrants,” as the U.S. military calls them, have in the past had wider movement around the 45-square-mile base, escorted by a contract security group called The Geo Group. Visitors They could spot them ride the ferry from Leeward side, where they are housed dormitory style in a renovated Marine barracks, to the Windward side, where they could do odd jobs and shop in the commissary.

Sisbarro emphasized that the Cuban asylum seekers are held in entirely different circumstances than the 171 war-on-terror captives at the U.S. Navy base at Guantánamo. The Cubans have access to a gym and a shop on the Leeward side, and an 11 p.m. curfew. Muslim Captives are in are in prison camps on Windward side, a ferry ride away, behind a special security gate leading to the barbed-wire-ringed prison camps.

Of the 33 migrants, 21 are approved for resettlement in nations other than the U.S., typically Latin America and Europe. The State Department is evaluating the other cases.