Horner, 51, worked for Swedish Radio and had both Swedish and British nationalities. According to Col. Najibullah Samsour, a senior police official, Horner was talking to a security guard outside a restaurant about a story he was working on, when a two men dressed in "traditional clothing" walked up to him and one of them shot him in the face with a pistol.
"Police are continuing to their efforts to arrest the culprits of the incident," police said in a statement.
The location is reminiscent of the Lebanese restaurant in which 21 foreigners were killed in an attack in January.
Horner had previously been based in New York and London and was only recent assigned to Kabul. No one has claimed responsibility for the killing but the attack has only intensified the concerns many foreigners, especially diplomats, have had about living in Kabul.
Swedish journalist Terese Cristiansson called Horner a "legend" and said he was one of the best Swedish journalists she knew of.
“The only thing he always wanted and talked about was being in the field,” she said.
[The New York Times]