A roadside bomb killed 30 people in southern Afghanistan on Tuesday, officials said, in the deadliest strike on civilians since a NATO air raid earlier this month, The New York Time reported.
Increased fighting as a result of a growing Taliban insurgency and a bigger NATO-led force in Afghanistan has led to a rise in civilian deaths.
More than 1,500 civilians have been killed by violence in Afghanistan so far this year, the United Nations said last week.
It said 68 percent of the civilian killings were a result of militant attacks, while 23 percent were caused by Afghan and foreign troops led by NATO and the U.S. military.
In Tuesday's strike, a bomb hit a bus outside the southern city of Kandahar killing 30 people including 10 children and seven women, the Interior Ministry said. At least 39 people were wounded.
Provincial government spokesman Zalmai Ayoubi said the bomb went off on a highway where an explosion had killed three civilians a day earlier. He blamed the Taliban for planting the devices.
Homemade bombs have become by far the deadliest weapon used by insurgents fighting Western and Afghan government forces, and civilians are frequently killed in the blasts.
The Taliban usually distance themselves from blasts when civilians are the victims.
The latest attack comes at a time of growing disquiet over the foreign mission in Afghanistan. The Taliban has grown in strength in recent months, and NATO countries have suffered growing casualties, eroding support for the war at home.