KABUL, Afghanistan - 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.

Fighting usually increases in Afghanistan as the weather warms and insurgents climb back over the mountainous border with Pakistan. This year, NATO has pushed further into Taliban strongholds in the south and has said their goal is to hold these areas so that militants cannot re-establish themselves.

The next couple months are particularly key for the United States, because President Barack Obama has pledged to start drawing down troops in July.

The suicide attack in eastern Laghman province also killed four Afghan soldiers and an interpreter. The Taliban claimed responsibility for the bombing and spokesman Zabiullah Mujahid said Sunday that the soldier was a sleeper agent who had been in the army for years and had been in contact with Taliban operatives for "a long time."

He said the soldier had only been at this specific base for one month. Previously, the Taliban had said the soldier had only joined the army a month ago.

Attacks by insurgents donning security uniforms are a relatively rare but recurrent problem as NATO and Afghan forces work more closely together. Afghanistan's security forces are also ramping up recruitment of Afghan soldiers and policemen so they can take the lead in securing their nation by the end of 2014, adding more than 70,000 police and soldiers last year in an effort to reach 305,000 troopers by the end of this year.

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.

Many of the more than 40 countries contributing troops to the U.S.-led effort in Afghanistan are dealing with eroding support for the mission at home as the war drags into its tenth year.

French Defence Minister Gerard Longuet arrived in Afghanistan Sunday to meet with his nation's troops and Afghan leaders. He met with French troops at the main southern base in Kandahar province, said Lt. Col. Eric de Lapresle, a spokesman for French forces in the country.

Longuet told soldiers at the military hospital there that he was proud of their work in the war-ravaged country. He is also expected to meet with political and military authorities in Kabul, de Lapresle added.

Some 3,850 French troops are deployed in Afghanistan as part of the NATO mission fighting the Taliban, mainly in Kapisa and the Surobi district north and east of Kabul.

It was unclear whether Longuet, named defense minister in late February, would discuss efforts to win freedom for two French journalists kidnapped in December 2009.