KANDAHAR, Afghanistan — A bus packed with Afghan civilians hit a roadside bomb near the southern city of Kandahar Tuesday, killing 30 people and wounding 39, underscoring the dangers civilians face as the eight-year war turns increasingly violent.

Militants are planting more roadside bombs than ever. The explosives are intended to kill U.S., NATO and Afghan troops but kill far more Afghan civilians than they do soldiers.

"The enemies of Afghanistan are planting mines on the main highway and killing innocent women and children," said Sardar Mohammad Zazai, Kandahar province police chief.

The bus hit the bomb on the western outskirts of Kandahar city, in a militant-controlled district called Maiwand. Nine women and seven children were among the 30 dead, Zazai said. Another 39 were wounded.

Some of the more severely wounded passengers were taken to a NATO base for treatment, said Bismullah Khan, the police chief in Maiwand. Others were taken to the main hospital in Kandahar.

"An explosion hit the bus. I don't know what happened. When I came to, I got out of the bus and saw that the bus was totally wrecked," Lal Jan, a survivor, said while in Kandahar's hospital.

Another survivor, an elderly woman named Zulaikha Bibi, cried over the death of her daughter-in-law. Two of her nephews were wounded.

The bus had been travelling from the western province of Nimroz to Kandahar city, a trip that winds through some of the country's most dangerous districts in Helmand and Kandahar provinces.

U.S. and NATO troops have long come under criticism for the civilian deaths they have caused, often in airstrikes. But U.S. military officials say they believe the Taliban will also face a popular backlash for all the civilian deaths caused by militant-planted roadside bombs.

A UN report issued Saturday said August was the deadliest month of the year for civilians because of violence from the insurgency. A total of 1,500 civilians died in Afghanistan from January through August, up from 1,145 for the same period of 2008.