Three more NATO service members were killed in attacks in Afghanistan on Saturday, the international coalition said, making a total of eight killed on one of the deadliest days for NATO troops this year.

The three deaths announced Sunday came from two separate bomb attacks in the south on the same day that five NATO service members were killed in a suicide bombing by a Taliban sleeper agent at a U.S. base in the east.

NATO officials have said they expect a particularly violent spring and summer in Afghanistan as insurgents try to pour back into areas taken over by international troops over the winter.

NATO has not identified the nationalities of any of the dead. The international military coalition typically waits for national authorities to make such announcements.

The majority of troops in both the east and south are American, though there are forces from other nations in both regions.

The latest deaths make 23 NATO service members killed so far this month in Afghanistan and 125 killed so far this year.