Mexican authorities searching for 43 students who disappeared after a protest last month are investigating a suspected mass grave.

Attorney General Jesus Murillo Karam said the testimony of two arrested members of a drug gang had led them to the site, in southern Guerrero state.

Reports claim that the students were handed to the gang by local police.

Earlier this month another mass grave was found, but the bodies unearthed did not belong to the students.

Dozens have been arrested and the state governor has resigned over the case.

The mayor of the town of Iguala, where the abductions took place, his wife and the police chief are all being hunted by the authorities.

They allegedly ordered the police to hand over the students to gangsters.

Eyewitnesses say they saw the students being bundled into police cars after the police shot at buses carrying the students, killing three of them.

The latest grave site in the town of Cocula, about 17km (10 miles) from where the students last were seen.

Mr Murillo Karam said that two of the four suspects arrested on Monday may have provided some valuable information.

He said that they had admitted to "having received a large group of people" on the night of 26 September, when the 43 students were last seen.

"We have the people who carried out the abduction of these individuals," Mr Murillo Karam told reporters.

He said the other two suspects detained on Monday apparently worked as lookouts for the gang. The suspects have not so far been identified.

The four men arrested men are all believed to be members of the group behind the abductions, called Guerreros Unidos.

The disappearances shocked Mexico and sparked nationwide demonstrations.

One month on, frustration is growing with no word on the fate of the students.

(BBC)