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.

NATO is in the first phase of handing security over to Afghanistan's army and police in a gradual process due to be completed in approximately three years.