A Pakistani rail official says there have been five rocket attacks over the past 10 days. Officials suspect that ethnic Baluch tribesmen seeking larger payment for use of the region's resources are behind the attacks.
The train service connects Quetta, the capital of Pakistan's southwestern Baluchistan Province, with Iran's border town of Zahedan.
Pakistan Railways operates a fortnightly passenger service and a weekly freight service on the line.
(AP)