Islamabad, Jan 15 (IANS): At least 20 schoolchildren and two other people were killed and many injured when a school bus collided with a truck in Pakistan's Sindh province Wednesday, a media report said.

According to Geo News, 20 students, a teacher and the bus driver were killed in the accident in Nawabshah city. An earlier report said all 22 killed were pupils.

However, Xinhua said the 22 dead included 16 children. At least 15 other people were injured when a heavy trailer hit a school bus and a passenger bus.

It said a teacher, a bus driver, a school watchman and three passengers were among the dead.

The students were aged between 10 to 16 years, Geo News said.

Doctors said the condition of some of the injured was critical.

President Mamnoon Hussain expressed deep shock and condoled the accident.

The president, in a message to the parents of the victims, said he was shocked over the sad demise of the students, the Associated Press of Pakistan reported.

He asked the authorities to ensure proper medical care for the injured students.