MEXICO CITY — Convicted drug lord Joaquin “El Chapo” Guzman, who twice pulled off brazen jailbreaks and is fighting to avoid extradition to the United States, was transferred to a prison in northern Mexico near the Texas border early Saturday.

Lawyers for Guzman, who was recaptured in January, have filed multiple appeals against their client being sent to the U.S., and Mexican officials have said it could take as long as a year to reach a final ruling. There was no immediate indication that the transfer could be a sign that the process is nearing conclusion.

The Sinaloa cartel boss was moved from the maximum-security Altiplano lockup near Mexico City to a prison in Ciudad Juarez, a security official told The Associated Press, without giving a reason. The official was not authorized to discuss the matter publicly and spoke on condition of anonymity.

Mexico’s National Security Commission said in a statement that the transfer was in line with security protocols, and it has rotated more than 7,400 inmates nationwide as part of a security strategy implemented last September.

Michael Vigil, the former head of international operations for the U.S. Drug Enforcement Administration, said Guzman was moved because of security concerns. Vigil, who said he had been briefed by Mexican officials, did not specify those concerns or say whether Mexican officials had information about possible new escape plots. He also did not specify the officials with whom he spoke.

Jose Refugio Rodriguez, an attorney for Guzman, confirmed that he was sent to the Cefereso No. 9 prison. He said Guzman’s defense team was not notified beforehand, and one of his lawyers was traveling to Juarez to try to meet with their client.

“I don’t know what the strategy is,” Refugio told The Associated Press. “I can’t say what the government is thinking.”

He confirmed that Guzman’s lawyers are still trying to block extradition.

Guzman faces charges from seven separate U.S. attorneys’ offices, including in Chicago, New York, Miami and San Diego.

A U.S. Customs and Border Protection spokesman in El Paso, Texas, referred inquiries to U.S. Immigration and Customs Enforcement, which did not immediately respond to telephone and email messages. Messages left with representatives of the U.S. Attorney’s Office and the U.S. Marshals Service in El Paso also were not returned immediately. The U.S. Justice Department declined to comment.

“El Chapo” first broke out of a Mexican prison in 2001. He was recaptured in 2014, only to escape the Altiplano lockup the following year through a milelong tunnel dug to the floor of the shower stall in his cell.

Mexican marines rearrested him in the western state of Sinaloa in January, after he fled a safe house through a storm drain.

He was returned to Altiplano, where officials beefed up his security regimen. Guzman was placed under constant observation from a ceiling camera with no blind spots, and the floors of top-security cells were reinforced with metal bars and a 16-inch layer of concrete.