Two Finnish aid workers were shot dead Thursday, July 24 in the western Afghan city of Herat, officials said, according to the Associated Press.

The two women were riding in a taxi when they were shot dead by two men on a motorcycle, said Sami Wafa, the chief of staff of the Herat governor. Herat police spokesman Raouf Ahmadi said the taxi driver had been detained as part of the investigation.

Finland's Foreign Ministry confirmed that two Finnish citizens have died in Afghanistan. Spokesman Keijo Norvanto said they worked for the International Assistance Mission, an aid group which has been operating in Afghanistan since 1966. The organization could not immediately be reached for comment.

"We are faced with a great tragedy," Finland's Prime Minister Alexander Stubb said in a statement. "Finland requires that a thorough investigation be conducted to bring those guilty to justice. Finland must also reassess the security situation in Afghanistan."

Earlier on Thursday, a bombing in a market in northern Afghanistan killed six people, including a young girl, while a separate attack in the east killed a local police commander and his bodyguard, officials said.

The attack in the market was aimed at a police car but the police escaped unharmed, said Sonatullah Timor, the spokesman for the Takhar provincial government. The bomb, which was placed on a motorcycle, wounded 26 people, including children, he said.

It was not immediately clear who carried out the attack, but Taliban insurgents frequently target the country's security forces.

In a separate incident, a suicide bomber detonated his payload at a checkpoint in the eastern Nangarhar province, killing a local police commander and his bodyguard, according to police spokesman Hazrat Hussain Mashraqiwal. He said the bomber shook hands with the commander before the explosion. The Taliban claimed responsibility for the attack in a media statement.