Peasant activists described numerous arrests, disappearances, beatings and torture as troops and police searched homes and vehicles for weapons over the past few days.
In the Pacific state of Guerrero, where 60 masked, well-armed and neatly uniformed guerrillas calling themselves the People's Revolutionary Army (EPR) appeared out of nowhere last month, the army admitted that these were its targets. Elsewhere, the operations were billed as "reforestation", "social work to overcome hurricane damage" or anti-narcotics actions. But peasant leaders said the military clearly feared the Guerrero movement could have a "domino effect" in the largely neglected, poverty-stricken southern states.
The brief but dramatic appearance of the EPR guerrillas, including a dozen women, at a peasant memorial service not far from the tourist resort of Acapulco, came two and a half years after the Zapatista National Liberation Army (EZLN) stunned Mexico with a two-week insurgency in the south-eastern state of Chiapas. The Zapatista leader, "subcomandante Marcos", this week denied any links with the EPR and noted that the latter were far better armed and equipped than his own army which has not fired a shot since January 1994 and now emerges from the Lacandon jungle only for peace talks with the government.
The government of President Ernesto Zedillo, however, is said to be concerned that individual peasant groups with similar motivation - putting an end to centuries of neglect and exploitation by wealthy landowners - could further weaken the increasingly fragile rule of his long-mighty Institutional Revolutionary Party (PRI).
The appearance of the EPR on 28 June, when they fired volleys into the air IRA-style at a memorial service for 17 peasants massacred by police a year earlier, came as statistics showed 1,000 Mexican families controlled one-quarter of the country's wealth and 23 new Mexican billionaires had been created in the last seven years.
As well as a sweep by 12 battalions of 600 men each in Guerrero, army raids have been reported on peasant activists in the states of Puebla, Veracruz, Oaxaca and Hidalgo. In Puebla, intelligence reports said troops were looking for 16 Liberation Theology priests accused of operating clandestinely in support of armed peasant groups. The "Red Padres", who favour radical action, were widely believed to have used short-wave radios to help the Zapatista guerrillas organise for several years before their insurgency.
In Guerrero, where peasants live in mud huts without water or electricity a stone's throw from Acapulco's glitzy hotels, clubs and casinos, human rights groups said middle-aged peasant activist Jose Nava Andrade had been tortured by men claiming to be government agents or policemen. Mr Nava said he was kidnapped for four days, blindfolded, taken to a place said to be where the EPR had appeared, and strung up on a tree before receiving electric shocks to his testicles from a portable torture device. The men demanded he name members of the guerrilla group but Mr Nava, now free and under medical care, insisted he had no idea.
Apparently believing that a local peasants' solidarity group, the Peasant Organisation of the Southern Sierra (OCSS), was the foundation for the EPR, police last week detained OCSS leader Hilario Mesino on charges related to a peasant's protest last year.
Mexican military officers believe the EPR is made up of OCSS members and leftists who fought with Seventies local guerrilla leader Lucio Cabanas and his Party of the Poor. A secret police and military force called the White Brigade killed Cabanas in 1974 but he remains a hero in Guerrero.
Cabanas's brother David, in prison in Mexico City for later guerrilla activity, said in an interview this week that the EPR had appeared "as a result of social margination, poverty and political repression. The people do not want to take up arms. They are forced to".
"The government does not want to admit such groups exist," the left- wing Senator Heberto Castillo said. "But they do. They're there because of hunger and misery. The only surprise is that there are not more such groups. There will be if the government does not change."
While the 60 EPR guerrillas disappeared into the lush Guerrero mountains as quickly as they had appeared on 28 June, they were thought by some local residents to have been responsible for the ambush of a local leader of the PRI last Monday. Victor Ayala, 55, and his bodyguard, driving a pick-up truck with PRI markings, were killed in a hail of bullets not far from the beach resort of Zihuatanejo. Residents said 20 men in hoods and dark clothes opened fire on the vehicle.
In their latest communique, the EPR predicted a clash with the army if troops continued to sweep villages and round up peasants. Signed by "Commander Antonio", the communique described the group as an insurgent force under the Geneva Convention and called on the army and government to respect the convention "in its treatment of the civilian population and prisoners of war".