The international military coalition in Afghanistan says two of its service members have died following the blast from an improvised explosive device in the southern part of the country.

NATO said in a statement that the two were killed Thursday, but did not provide any other details or nationalities.

According to the independent online site iCasualties.org that monitors the number of coalition deaths, a total of 421 members of the coalition have died so far this year in Afghanistan.

Also Thursday, Afghan officials say a roadside bomb killed a Turkish engineer working on a project in Herat province.

Another roadside bomb killed five Afghan soldiers in the eastern province of Khost on Wednesday.