The attacks on Thursday killed the employee of the Western-funded Coordination of Humanitarian Assistance (CHA) relief agency in the northwestern province of Faryab, provincial CHA head Khan Mohammad Sameem said.
Three other aid workers were wounded.
Faryab's governor, Mohammad Aamir Latif, blamed Taliban fighters for the attack.
The ambush followed one a week ago in which five local aid workers were killed in the southern province of Kandahar.
In another attack, also on Thursday, Taliban fighters blew up a car, killing Nafas Khan, police chief for Zaranj, the provincial capital of Nimroz in the south.
Khan's aide was also killed in the blast triggered by a remote-controlled device, a senior provincial official said, who accused the Taliban of carrying out the attack.
An intelligence official was killed in a roadside bomb in the eastern province of Kunar, officials said.
Zaranj blast confirmed
Mohammad Yousuf, a spokesman for the Taliban, confirmed his group was behind the blast in Zaranj, but had no information about the attack on CHA.
The latest surge in attacks is part of the violence that has claimed 1100 people, mostly fighters, but also more than 50 US soldiers in Afghanistan this year, the bloodiest period since US-led troops overthrew the Taliban in 2001.
The Taliban has vowed to drive out foreign forces from Afghanistan and topple President Hamid Karzai's government that was installed after the ousting of the Taliban government.