The number of Mexican children abducted, recruited by organized crime, mutilated and murdered has surged alarmingly, the Inter-American Commission on Human Rights said Monday.

The grim report from the OAS-affiliated rights body comes as Mexican authorities are scrambling amid a massive scandal over 43 college students missing and feared dead.

The group's investigator Rosa Maria Ortiz visited the country earlier this month and "received information indicating that there has been an alarming increase in the figures of (missing) children who have not been found.

"The (Mexican government), meanwhile, has not given data," she stressed.

Several organizations report that at least 2,000 children were slaughtered between 2006-2014, often with "extreme forms of violence," she said.

There have also been a huge number of minors being forcibly recruited to work for organized crime, especially in poorer areas. 

Of Mexico's 118 million people, seven million still live in extreme poverty, many of them in Guerrero state and neighboring Oaxaca and Chiapas states. 

These areas, as well as several in Mexico's north, have seen years of bloodletting between rival drug cartels warring over turf and shipping routes.

Ortiz also urged President Enrique Pena Nieto's government "to investigate with greater urgency the case of the 43 students -- swiftly and impartially."

Mexican authorities had stepped up their efforts to find the students, who disappeared more than three weeks ago, using dogs, horses and divers to broaden the search.

About 50 vehicles, carrying some 200 members of a special division of the federal police, arrived Sunday in Xonacatla, which is located close to the town of Iguala in Guerrero state, where the students disappeared on September 26.

Authorities said the search had been expanded to include bodies of water such as lakes and ponds, as well as in the numerous mines and caves of the mountains around Iguala. 

More than 1,200 security forces are now looking for the college students around Iguala, a town of 140,000 inhabitants.

Authorities say Iguala's police force shot at buses carrying the students on September 26 and handed them over to officers in the neighboring town of Cocula, who then delivered them to the Guerreros Unidos drug gang.

Mexican authorities announced Friday the arrest of the "maximum leader" of a drug gang accused of colluding with crooked police in the disappearance of the students. A total of 36 municipal officers have been arrested in the case.