The U.S. State Department plans to send a letter of protest to Mexican officials over the handling last week of the closure of three schools for troubled teenagers in Baja California, amid complaints from parents and school officials that Mexican authorities have yet to justify their actions.

More than 500 students and staff were forced to return to the United States and other countries after Mexican authorities closed the facilities in Ensenada and Rosarito Beach. The largest school, Casa by the Sea, housed about 550 boys and girls at a former hotel overlooking the Pacific Ocean.

Ken Kay, a spokesman for Casa by the Sea, denied that the facility had a punishment cell or an electric fence. And he cited a Mexican media report earlier this week that said a Mexican health official had found no evidence of abuse.