An incursion by Mexico’s Federal Police into a human rights office in Ciudad Juarez has sparked accusations of abuse of authority.

Five Federal Police trucks showed up at the offices of the Centro de Derechos Humanos Paso del Norte, or the Passage to the North Human Rights Center, on Sunday around 8:30 p.m., according to reports. No staff were on the premises, and around 20 agents, who did not have a warrant, entered forcibly and searched through files, according to staff members.

However, the Federal Police said that the officers did not intend to break into the facility, but were merely chasing suspected “narcomenudistas,” or retail drug dealers. According to the police account, they entered the building in order to arrest two suspects who had hidden inside. Police say the individuals were caught in possession of various drugs.

Critics of the government were unconvinced by the explanation. Jose Miguel Vivanco of Human Rights Watch. said that warrantless searches “can be especially harmful when they target human rights defenders, because they create a climate of intimidation that deters people from denouncing abuses.”

The incident comes as Juarez prepares for the Thursday arrival of the Caravan for Peace, whose leaders, such as poet and campaigner Javier Sicilia, have been harshly critical of President Felipe Calderon’s militarized approach to combating organized crime.

Mexico’s ongoing struggle against organized crime groups, which have helped turn Juarez into one of the world’s most dangerous cities, has put human rights groups at odds with the army and the Federal Police, especially in Chihuahua, where Juarez is located. Gustavo de la Rosa, the state’s human rights ombudsman, has catalogued hundreds of reports of military abuse in the region.