PESHAWAR (AFP) - Suspected militants shot dead a female health worker overnight in Mohmand Agency, residents and officials said Friday. An unknown number of assailants raided a health facility late Thursday and gunned down 35-year-old Nihar Begum in the village of Baotha in the Mohmand tribal district which borders Afghanistan. Residents blamed local Taliban for the killing. "They oppose women activities in every field," a resident told AFP. Local official Haseeb Khan confirmed the incident but said it was not immediately clear whether the attackers were local Taliban. "We have arrested three suspects and are interrogating them," Khan said. Armed men abducted and beat 11 health workers sent to a tribal area to administer polio vaccination forcing the suspension of the campaign in August last year. In February 2007, a health official in charge of a polio inoculation campaign was killed in Bajaur district in a bomb blast.