(Adds explosion at health department, official confirmation, background context on rising attacks and polio programme)

By Ahmad Sultan and Abdul Qadir Sediqi

Ghulam Dastagir Nazari, head of the immunisation programme at Afghanistan’s Health Ministry told Reuters the explosion took place at the entrance to the health department for the province of Nangarhar late on Tuesday morning.

Around the same time unknown gunmen shot vaccination workers at two separate locations in Jalalabad, killing two volunteers and one supervisor in the polio immunisation programme, all of them women, he said.

It was not clear who was behind the attacks. A Taliban spokesman did not immediately respond to request for comment.

A wave of assassinations have hit urban centres since peace talks began between the Taliban and the Afghan government last year in Doha, many of them targeting professional women as well as government employees, media and civil society members.

Three female journalists were killed in Jalalabad this month, an attack claimed by Islamic State. The government blames most targeted killings on the Taliban, who deny involvement.

The attacks came the same week the polio vaccination campaign for 2021 kicked off. The programme is led by the health ministry with the involvement of the United Nations’ children’s agency UNICEF.

Afghanistan and neighbouring Pakistan are the only two countries where the crippling disease is still endemic.

Militant groups including the Taliban have targeted health workers in the past. The U.N. mission to Afghanistan warned last year that health workers were increasingly at risk after a series of attacks. One attack on a Kabul maternity ward in May killed twenty-four people, including mothers and newborn babies. (Reporting by Ahmad Sultan in Jalalabad and Abdul Qadir Sediqi and Orooj Hakimi in Kabul ; Writing by Charlotte Greenfield; Editing by Andrew Heavens and Tom Hogue)