President Vicente Fox of Mexico yesterday promised an exhaustive investigation into Wednesday's assassination attempt on the governor of Chihuahua state, the first serious incident of political violence since Mr Fox assumed office.
Governor Patricio Martinez, a member of the Institutional Revolutionary Party (PRI), was in stable condition after the attack, apparently perpetrated by an ex-police officer dismissed from the force in 1996 after injuring her husband in a gun attack.
Mr Martinez is a popular candidate for presidency of his party after recapturing Chihuahua state from Mr Fox's National Action Party (PAN) in 1998.
The shooting came the day after a boy died in a letter bomb explosion, while two state officials were shot and injured in separate incidents.
The Martinez shooting occurred as President Fox made his first official visit to Chiapas state, in south-east Mexico, where Zapatista rebels led an indigenous uprising in January 1994. Mr Fox has made the resolution of the Chiapas conflict his highest priority, but has already run into criticism for failing to follow through on rebel preconditions.
Mr Fox agreed last month to release 100 Zapatista prisoners, dismantle seven army bases and send a peace accord to parliament for legislative approval. However, only 18 prisoners have been released and just four army positions abandoned, leading rebel assessors to question his commitment to peace.
Last Sunday, on his weekly television show, Mr Fox suddenly called on the rebels to surrender their weapons before any return to dialogue, a statement criticised by all political parties. "It was an invitation, not an order," responded Mr Fox.
The twists and turns in Mr Fox's Chiapas policy reflect pressures by army and business leaders, who fear a resurgence of Zapatista power. The rebel leadership will visit Mexico City next month, where they will address parliament as part of the drive to enshrine the San Andres peace accord in Mexican law. The limited autonomy peace accord was signed in 1996.
Mr Fox first invited the rebels to Mexico City, then balked at the notion of them arriving in their trademark balaclavas.