Several people were injured in a powerful explosion near the Chaman railway crossing in Quetta on Sunday, police said.

According to initial reports, the blast occurred when a passenger train was passing through the crossing.

The force of the blast derailed a couple of coaches of the train, officials said.

Rescue sources said the injured had been shifted to Civil Hospital Quetta, while emergency services continued relief operations at the site.

The sound of the blast was heard across the city, according to police officials.

The blast also shattered the doors and windows of nearby buildings.

At least four vehicles were also damaged in the blast.

Authorities imposed an emergency at all government hospitals in Quetta and summoned all medical staff on an urgent basis.

Balochistan chief minister’s special assistant for interior Babar Yousafzai said all relevant institutions had been placed on alert and urged the public to avoid gathering near the site of the incident.

“As soon as more details emerge, the media will be informed,” Yousafzai said.