JALALABAD, Afghanistan, June 15 (Xinhua) -- Four health workers were killed and three others wounded in separate shooting attacks during a polio vaccination drive in Afghanistan's eastern province of Nangarhar on Tuesday, local police confirmed.
The incidents occurred when gunmen fired on the polio vaccination teams in the provincial capital Jalalabad city and suburban districts of Khogiani and Surkh Rod at midday, provincial police spokesman Farid Khan told Xinhua.
Earlier on Tuesday, Afghan Public Health Ministry launched a nationwide campaign to give polio vaccination doses to millions of Afghan children under the age of 5.
Afghanistan and neighboring Pakistan are the only two countries in the world where polio cases are reported every year, according to Afghan public health officials.
No group has claimed responsibility for Tuesday's shooting attacks yet. Taliban militants and militants of the Islamic State (IS) are active in the province.
Earlier this year, three female vaccinators were shot dead in Nangarhar in a similar incident.