MEXICO CITY, Jan 11 (Reuters) - The United Nations said on Thursday it was deeply concerned that Mexican security forces may have violated human rights in responding to a gun battle near the seaside resort of Acapulco in which 11 people were killed.

The Mexican office of the U.N. High Commission for Human Rights said it obtained documentation of torture, fabricated evidence, poor detention conditions and searches conducted without warrants after the shootout on Sunday.

"The U.N. has strong convictions about the existence of human rights violations committed by security forces during the operation, which are profoundly troubling," the office said in a statement.

Officers arrested at least 30 people after the shootout south of Acapulco in the state of Guerrero, in which residents clashed with a self-appointed community police force.

Jan Jarab, representative for the U.N. rights commission in Mexico, called for the investigation of all deaths, including those that occurred during police proceedings.

He also described the aggression against journalist Bernardino Hernandez, who had to be hospitalized, as "particularly grave."

The United Nations did not specify whether the police or army may have committed abuses, but reports at the time said local police were involved in the operation.

Mexico's security forces, particularly its military, have been embroiled in multiple human rights scandals in recent decades, including extrajudicial killings of gang members and the 2014 disappearance of 43 students near a military base in Guerrero.

For years, Guerrero has experienced a wave of crimes and disappearances linked to the bloody battles waged by drug gangs for control of the territory. (Reporting by Veronica Gomez; Writing by Daina Beth Solomon; Editing by Paul Tait)

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