Zabul governor's spokesperson Gul Islam Seyal said 185 people were also injured when a Taliban suicide bomber detonated his explosive-laden vehicle near the government hospital in the city of Qalat, capital of insecure Zabul province, on Thursday at around 6 a.m., Efe news reported.
"In yesterday's heinous bombing, 39 residents were killed and another 185 injured, 40 of whom are in a critical condition," he said.
Several bodies were recovered from under the rubble of the buildings damaged in the explosion.
The powerful blast damaged several nearby buildings, including a high school complex. Four students were among the dead and 20 others were injured.
Among the dead are two security personnel. The rest are civil, including women and children as well as doctors and patients at the hospital.
Seyal said almost all services have been paralyzed at the hospital that was the only well-equipped health centre in the province.
The hospital's intensive care unit and dining room were destroyed while several ambulances and vehicles were badly damaged in the blast.
The truck bombing was claimed by the Taliban with its spokesperson saying that the target was a nearby building that houses the government's intelligence department, the National Security Directorate.
Seyal said the attack was carried out near the hospital gate and the explosion only damaged the boundary wall of the National Security Directorate building. He said personnel in the spy agency were unhurt.
There has been a surge in militant attacks in Afghanistan in the past few weeks ahead of the presidential election on September 28.
This year, 133 attacks on health facilities and personnel were recorded across the country, United Nation Office for the Coordination of Humanitarian Affairs (UNOCHA) said.
( With inputs from IANS )