( CNN ) -- Federal troops are on the way to a southern Mexican town where 43 students went missing , and local police have been ordered to lay down their weapons . Mexico 's federal Gendarmerie force will take over security in the southern municipality of Iguala along with the Mexican Army , the head of the country 's National Security council told reporters Monday . Monte Alejandro Rubido Garcia , head of the commission , said President Enrique PeÃ±a Nieto had ordered the takeover , according to Mexico 's state-run Notimex news agency . Mexican Army and Federal Police forces are on the way to the municipality , where authorities are investigating the disappearance of 43 students after a night of violence last month . Authorities have accused local police of involvement in shootouts the night of September 26 , when gunmen opened fire on buses carrying dozens of students and soccer players . Since then , 43 students from a rural teachers ' college have been missing . Investigators found unmarked mass graves near the town over the weekend , and they say the graves could be connected to the case . State prosecutors say the remains of at least 28 people were in the graves , but the bodies were covered with gasoline and burned before they were buried , and it could take months to identify them . On their Twitter account Monday , Mexican Federal Police posted a photograph of vehicles on the way to Iguala , lights flashing . The case has drawn widespread attention and sharp criticism of officials in Iguala and Mexico 's Guerrero state . `` Like all of Mexican society , I am outraged and troubled by this situation , and I assure you there will not be impunity , '' PeÃ±a Nieto said in a Twitter post Monday . Mexico 's Attorney General 's Office also said Monday that it was forming a special team to investigate the students ' disappearance . CNNMexico.com contributed to this report .
Mexican federal forces are taking over security in the town of Iguala . Many students went missing there more than a year ago , and mass graves were found . ` ` I am outraged and troubled by this tragedy , '' Mexico 's president says .