"MEXICO CITY -- Water-rights activists on Tuesday questioned the theory of Mexican state prosecutors that the killing of a state legislator-elect this month was orchestrated by his designated substitute."

"At least 26 people were killed and as many injured when a Pemex gas facility burst into flames in northern Mexico on Tuesday, one of the worst accidents to hit the state oil monopoly in recent years."

"Nature assesses the aftermath of a series of nanotechnology-lab bombings in Mexico -- and asks how the country became a target of eco-anarchists."

"President Felipe Calderón of Mexico announced Wednesday that the national oil company, Pemex, had struck oil in deep water, its first success after years of exploration in the deeper reaches along the bottom of the Gulf of Mexico."

"Tropical storm Ernesto weakened on Wednesday as it dumped heavy rains over Mexico's southern Yucatan peninsula and headed toward the Gulf of Mexico, where the country's main oil operations are located."

"An eight-year environmental pact to reduce air, water and chemical pollution along the U.S.-Mexico border will be signed by dignitaries from both countries, Environmental Protection Agency officials said Tuesday."

"Tropical Storm Ernesto picked up speed in the western Caribbean on Monday as it moved toward Mexico's Yucatan Peninsula, dousing Honduras and Belize on its way."

"Mexico's new president is unlikely to implement much of the sweeping climate change law signed in June by outgoing President Felipe Calderon amid inevitable resistance from industry and his party's focus on accelerating economic growth and ramping-up oil and gas production, policy experts said."

"A record drought in northern Mexico has prompted warnings that the region's climate may have changed for good."