A British man and his colleague were murdered outside their office in Kabul by a security guard who then committed suicide, Afghan police said.
David Giles, an employee of shipping firm DHL, died in the gun attack at around 8.30am local time, raising concerns for the safety of Western workers in the capital.
He was killed alongside a South African colleague. The pair were reportedly director and deputy director for DHL in Afghanistan, but the Foreign Office has not yet confirmed any more details about the Briton.
Mr Giles' ex-wife Julia Wilson, who lives in Hull, told The Times: "I am just deeply shocked. I was married to that man, he is my son's father. I can't believe what happened." The former couple, who divorced three years ago, have a 10-year-old son, the newspaper said.
DHL has closed its office in Kabul while a police investigation is carried out, but branches in Baghram and Kandahar remain open.
A spokesman for DHL said: "At this difficult time our thoughts are with the families, friends and colleagues of those who have lost their lives under such tragic circumstances. DHL is fully co-operating with authorities investigating the incident."
Thirteen people have been arrested in connection with the shooting, the circumstances of which are not yet clear.
Mirza Mohammad Yarmal, the Interior Ministry official in charge of criminal investigations, told reporters the guard, who was employed around a month ago, opened fire on the pair before turning the gun on himself.
A Taliban spokesman denied involvement in the attack, but the group has already admitted murdering charity worker Gayle Williams who was gunned down on her way to work on Monday.
Her sister Karen Williams told a press conference in Kabul that Gayle was working with severely disabled children to help integrate them into the community. She said: "If Gayle could talk to us now, her view would not have changed. Her faith in the Afghan people would remain the same."
Commentary: There are several Ghanaians and those of Ghanaian origin serving in the British Army, US Army or in other capacities in Afghanistan and Iraq. We pray for their safe return.