KARACHI, Pakistan (AP) _ Monsoon rains have left more than half of Pakistan's largest city without electricity for a week. At least 40 people have been killed, many electrocuted by downed power lines.

Nearly a foot of rain has fallen on Karachi in the last two weeks, the heaviest rainfall in 17 years. The downpour has wreaked havoc on the antiquated power lines that make up its electrical system, and hundreds of feet of downed lines are buried in the flood water.

The power outages have prompted daily riots in which at least two people have been killed.

One man was killed when police opened fire on protesters outside government buildings now cordoned off by hundreds of heavily armed police. Another died in cross-fire between police and demonstrators.

The power cut has cost business and industry in Karachi, a city of 9 million people that is Pakistan's industrial heart, an estimated $100 million in the past week, said Habib Charania, a spokesman for the Pakistan Chamber of Commerce and Industry.