Over a dozen low intensity bombs went off on railway tracks near the Pakistani port city of Karachi and in other parts of southern Sindh province today, forcing authorities to suspend train services.

No one was hurt as no trains were near the sites of the blasts, railway officials said.

Senior official Mr Zafarullah Kalur said the blasts damaged several feet of tracks across Sindh province, of which Karachi is the capital. The blasts occurred before and after dawn within a space of hours.

About 14 blasts were reported in different places, including Karachi, Hyderabad, Sukkur, Nawabshah, Khairpur, Ghotki and Mirpur Mathilo. Footage of television showed tracks damaged by the explosions.

Mr Kalur said trains were stopped after the blasts and teams were sent to repair the damaged tracks so that services could be restored.

No group claimed responsibility for the blasts. Pamphlets bearing the name of Sindhu Desh Liberation Army, a hitherto unheard of group, were found near the blast sites, Dawn News channel reported.

In the past, a little known group called the Sindh Liberation Army had taken responsibility for similar blasts.

Officials said they did not have any clues as to who was behind today’s blasts. This was the second time that tracks were targeted this year.

Small blasts on railway tracks have been occurring for the past two years, officials said.

Railways General Manger Mr Saeed Akhtar said the blasts were a terrorist act and that security for tracks had been furthered tightened after the attacks.

Coordination with provincial authorities will be improved to step up patrolling along tracks to avert such incidents in future, he said.

Civil and railway police arrived at the sites of the blasts and registered cases against unidentified suspects.

Thousands of people travel by trains in Pakistan every day as they are a cheaper mode of transportation and the blasts could trigger fears among passengers.