By Gul Yousafzai
QUETTA, Oct 21 (Reuters) - At least five passengers were killed and 16 injured when a train was bombed and derailed in restive southwest Pakistan on Monday, officials said.
It was not immediately clear who was responsible for the bombing, but arid western Baluchistan province is home to several separatist insurgents besides the Taliban and banned sectarian groups.
The train was traveling from the garrison city of Rawalpindi to the provincial capital, Quetta. Several carriages were destroyed in the explosion, which took place 200 km (124 miles) from Quetta, one of Pakistan's most violent cities.
"The explosives had apparently been planted on the railway tracks as the explosion created a crater several feet deep," said provincial government official Asad Gillani.
Most of the passengers were returning to Quetta after celebrating holidays at home, said another official. There were three brothers were among the dead.
Separatist insurgents in Baluchistan accuse the government of exploiting the mineral-rich region while leaving inhabitants in poverty.
(Writing by Syed Raza Hassan; Editing by Katharine Houreld and Clarence Fernandez)