By Julio-Cesar Chavez

SUNLAND PARK, N.M., April 24 (Reuters) - The leader of an armed militia group that spent the past two months detaining migrants at the U.S.-Mexico border has been hospitalized after he was attacked in the prison where he was awaiting trial on federal firearms charges, his attorney said.

Larry Hopkins, 69, was in hospital with broken ribs after being attacked on Tuesday at the Dona Ana County Detention Center in Las Cruces, in southern New Mexico, attorney Kelly O'Connell said.

A spokeswoman for the Dona Ana County center could not be reached for immediate comment early on Wednesday.

The FBI on Saturday arrested Hopkins, leader of the United Constitutional Patriots group, on charges of being a felon in possession of firearms and ammunition dating back to a 2017 investigation.

His UCP group on Tuesday abandoned the camp in the New Mexico desert where they had spent two months detaining thousands of illegal migrants. The departure came after state officials and civil liberties groups accused them of violating migrants' rights and the owner of the property where they were camped ordered them out.

O'Connell said he had spoken with Hopkins by phone.

"This guy is very high profile. So, if he gets put into jail and is immediately attacked after his first hearing just a few days after being put in there, can Dona Ana County correctional protect high profile defendants?" O'Connell asked.

O'Connell said he would ask officials about their plans to ensure his client's safety at his next scheduled court hearing on April 29 in Albuquerque.

He said he did not know what had provoked the attack. (Additional reporting by Peter Szekely in New York; Editing by Scott Malone and Bernadette Baum)

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