MEXICO CITY (BNO NEWS) – Mexican authorities on Wednesday announced the arrest of seven individuals that are the alleged responsible of the killing of 72 migrants in northern Mexico.

Alejandro Poire, the government’s security spokesperson, said that four of the suspects were arrested on September 3 by Mexican marines in San Fernando, Tamaulipas.

The Navy servicemen were attacked by the four criminals and detained them along weapons and ammunition. The Marines also found two corpses in a mass grave. Poire added that in a subsequent operation, three more individuals were detained in relation to the massacre that involved Central and South American migrants.

So far, Mexican authorities have identified one Ecuadorian survivor and returned him to his native country as well as another Honduran survivor. During the arrest operations, three other criminals were killed.

Last month, a group of migrants from South and Central America who had initially crossed into Mexico through its southern border, were attacked by a criminal group as they were seeking to enter into the United States.