MEXICO CITY -- Eighty-eight schools in a northern Mexico state will not open Monday along with the rest of the country because of the danger of water contaminated by the spill of 40,000 cubic meters of acids from a copper mine into two rivers this month.

Sonora state civil protection director Carlos Arias said Sunday that the schools in the seven municipalities most affected by the Aug. 6 spill may be able to open in a week, once officials ensure safe drinking water for students.

Officials have distributed more than 4 million litres of drinking water over the past week using tanker trucks, reaching 80 per cent to 90 per cent of people in the area. Arias said they had not yet reached people who live in isolated communities.