Gunmen attacked a UN polio vaccination campaign in Pakistan's southern city of Karachi, seriously injuring one of the doctors, according to The New York Times.
The violence took place as the UN convoy, part of a three-day polio vaccination campaign, was traveling through the Karachi neighborhood of Gadap.
More from GlobalPost: Taliban bans vaccinations in Pakistan until US drone strikes end
Gunfire rained down on the UN vehicle, and a Ghanaian doctor was shot in the abdomen, prompting an investigation by Pakistani and UN officials, said NYT.
It's the latest complication in the UN polio vaccination effort, with the Taliban earlier banning vaccinations in Pakistan in retaliation for US drone strikes.
“We don’t know exactly why this shooting took place, but it is probably related to the polio eradication program,” Guido Sabatinelli of the World Health Organization told NYT from Karachi.