Emergency anti-pollution measures in Mexico City for a second day

The authorities in Mexico City are extending emergency measures for a second day after air pollution reached dangerously high levels.

Since Tuesday more than a third of the cars have been ordered off the roads, factories have been forced to reduce output, and schoolchildren are not allowed to play outside.

The city, one of the world's biggest and most polluted, is covered by a thick veil of smog, along with smoke from surrounding forest fires.

The Mexican environment minister (Julia Carabias) has said no significant rainfall is expected for at least another two weeks and warned that the worst pollution is still to come.

From the newsroom of the BBC World Service