Up to 25 people on board an Afghan army helicopter died on Wednesday after it crashed in Farah province, including provincial chiefs and senior army officials.
Two helicopters were flying together from Farah to Herat province when one of them lost control, officials said.
A spokesman for the governor western Farah province said bad weather and low visibility caused the aircraft to crash, but the Taliban said their militants shot it down.
At least 20 crew and passengers were on board including high-ranking Farah provincial council members and military officials, Najibullah Najibi a spokesman for the 207 Zafar Military Corps told Tolo News.
Farid Bakhtawar, the outspoken head of Farah Provincial Council was on the flight as well as other chief members of the council and Nematullah Khalil, the deputy commander of the army corps for the western region.
Bakhtawar was a major figure in battling the Taliban in the battle for the city of Farah which the militants besieged and threatened to take over in May.
The Taliban are seeking to remove the government after their ouster by US-led forces in 2001.
On Wednesday a suicide bomber blew themselves up near the gate of Afghanistan's largest prison, killing at least six people.
There was no immediate claim of responsibility for the attack on the Pul-e-Chakhi prison, which houses scores of Taliban inmates.
Interior ministry spokesman Najib Danish said the attacker detonated his explosive near a vehicle carrying prison employees.
Six people died near the gate of the prison on the eastern outskirts of the city and eight were wounded, another government official said.
"The attacker walked towards a vehicle that was parked at a gate for security clearance. He blew himself up before the vehicle could enter the prison premises," the official said.
An Afghan news website said women security officials were in the vehicle at the time of the attack.