Kabul, Sep 19 (IANS): At least 15 people were killed and 70 others injured in a truck blast claimed by the Taliban militant group in Afghanistan's Zabul province on Thursday, authorities said.

The attack occurred at around 6 a.m. in the city of Qalat, capital of insecure Zabul province, the spokesperson of the governor of the region, Gul Islam Seyal, told Efe news while confirming the casualties.

Seyal said the "powerful bombing badly destroyed the hospital building and several nearby houses".

Most of the victims were "hospital health workers, patients and civilians from nearby houses", he said, adding that the number of victims could rise in the next few hours.

The injured were evacuated to other Qalat hospitals and to the neighbouring city of Kandahar.

Taliban spokesman Zabihullah Mujahid claimed responsibility for the attack and said it was directed against a National Security Directorate (NDS) building.

"Due to the attack most of the buildings and facilities (were) destroyed. A big number (of) intelligence officers, soldiers and employees killed and injured," Mujahid said in a statement.

There has been a surge in militant attacks in Afghanistan in the past few weeks ahead of the presidential election on September 28.