El Charco - A weekend army attack on suspected leftwing rebels in this tiny Mexican town 140 miles from Acapulco was a "massacre," local officials said yesterday, contradicting the government version of a clash with troops. Meanwhile in the southern state of Chiapas peace talks between the government and Zapatista rebels were in jeopardy yesterday after Mexico's main peace broker, Bishop Samuel Ruiz of San Cristobal, stepped down.