(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 Peña 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," Peña 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.