CHILPANCINGO, Mexico (Reuters) - Mexican authorities said on Friday that they were investigating local police in the capital of Guerrero state after the dismembered bodies of two young men were found inside plastic bags outside the beach resort of Acapulco.

State prosecutor Javier Olea said the young men had been arrested by Chilpancingo police last Saturday after a brawl at a Christmas fair and officers were suspected of later murdering them. Their bodies were found on Thursday. At least one other young man has disappeared.

State and federal police and military forces took over security operations in Chilpancingo on Thursday after more than 100 local police officers were suspended and put under investigation in the case, a state police spokesman said on Friday.

A growing number of criminal groups in Guerrero are battling over territory used to grow opium poppies for heroin production. Guerrero is one of the most violent states in Mexico. It is not uncommon for state, federal and military forces to replace local security forces suspected of corruption and ties to Mexico’s powerful gangs.

On Thursday, protests were held against local police and relatives of two missing youths told reporters they suspected police were involved in their disappearance.

In the nearby city of Iguala in 2014, 43 Mexican students were rounded up by corrupt police, who handed them over to a gang that burnt them in a nearby dump, according to a federal investigation.

Clashes between rival drug gangs contributed to a record high number of murders in Mexico last year. President Enrique Pena Nieto has pledged to get violence under control ahead of national elections this summer.