Three members of a polio vaccination team were killed in two separate incidents in Afghanistans Nangarhar province, officials said on Tuesday.

Provincial police chief Jumagul Hemat told dpa news agency that one member of the team was killed in Police District four of the provincial capital of Jalalabad.

The other two deaths took place in the city’s Police District seven.

Two suspects have been arrested in connection with the incidents, police said.

Initial investigations show that the health workers were killed by gunshots.

There was no claim of responsibility.

On Monday, Afghanistan started a five-day anti-polio campaign aimed at vaccinating 9.6 million children in 32 of the country’s 34 provinces.

About 3 million Afghan children were unable to get access to the polio vaccine during the past three years due to Taliban militants preventing door-to-door campaigns, according to the Health Ministry.

Healthcare workers frequently come under attack in the war-torn country.

Last yeat, gunmen attacked the maternity ward of a hospital in Kabul, killing 24 people, including several health workers.

Nangarhar is among the volatile provinces where Taliban and the Islamic State (IS) terror groups are active.

Earlier this month, gunmen killed three employees of a private TV network in the province.

The IS claimed responsibility for the attack.