By Jorge Dan
IGUALA Mexico (Reuters) - Authorities have found a mass grave in the restive southern Mexican state of Guerrero, the state attorney general's office said on Saturday, at a time when police are scouring the area for nearly four dozen people missing after a rash of violence.
The discovery was made just before midday in the northwestern outskirts of the city of Iguala. Local and state police cordoned off the entrance to road leading up a hill where multiple police vehicles had entered.
The state prosecutor, flanked by armed guards, visited the site, but only confirmed authorities were examining the grave.
"In the next few hours we will determine the cause of death and the number of bodies," said Jorge Valdez, a spokesman for the state attorney general's office, adding that bodies were being exhumed.
Iguala is located about 120 miles (193 km) south of Mexico City in the increasingly violent state of Guerrero, the site of clashes involving students, police and armed men last week. At least six people were killed in a spate of incidents.
The state governor said earlier this week that photos showed police had taken some of the students away. Twenty-two police officers were arrested in Guerrero on Sunday accused of killing two students during the clashes last week.
Local government officials criticized the police for showing an excessive use of force with the students in Guerrero, where gangs have evolved from a fragmented drug cartel and are fighting turf wars.
Thirteen of an original group of 57 missing people re-emerged this week. Some had hidden, others had gone home. Dozens are still unaccounted for.
Many mass graves have been found across Mexico in recent years and months, the legacy of grisly drug gang violence that has killed around 100,000 people since 2007.
Separately, Mexico's Attorney, General Jesus Murillo, said this week that three soldiers have been accused of homicide in a late June shootout in which 22 suspected gang members were killed.
Murillo said the three were part of a group of 8 soldiers held over the June 30 incident in Tlatlaya on the southern fringes of the State of Mexico, which borders Guerrero and Michoacan.
(Additional reporting by David Alire Garcia; Editing by Simon Gardner and Andre Grenon)