QALAT, Afghanistan, Sept. 4 -- At least 34 persons were killed and 21 others wounded after a long-distance bus collided with a truck along a main roadway in Afghanistan's southern province of Zabul on Sunday, provincial police chief said.

"The accident took place along Kabul-Kandahar highway in Jaldak locality roughly at 05:00 a.m. local time. The crash caused the vehicles to catch fire," Gen. Mirwais Noorzai told Xinhua.

The wounded, suffering from severe burns and fractures, were transferred to hospitals in provincial capital Qalat city and neighboring Kandahar province, the police chief added.

The number of the deaths was likely to rise as many of the injured were in critical condition and among the victims were several women and children, he noted.

Local officials said that the overloaded bus travelling from Kandahar to Kabul was carrying around 60 people.

Reckless driving might be the reason for the deadly accident and an investigation into the incident is underway, according to local officials.

Some 73 people were killed and several others wounded in a three-vehicle crash on the same highway on early May this year.