SAN JOSE (CBS SF) – A U.S. Army specialist from San Jose was killed in Afghanistan last weekend, military officials said Tuesday.

Delfin Santos Jr., 24, died Saturday in Kandahar after he was fatally injured in an enemy attack that involved a vehicle-based improvised explosive device in the Zabul province.

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Two other soldiers, Spc. Wilbel Robles-Santa, 25, of Juncos, Puerto Rico, and Staff Sgt. Christopher Ward, 24, of Oak Ridge, Tenn., who were in Santos’ unit, also died in the attack.

The soldiers were accompanying a group of American officials and their Afghan counterparts who were on their way to donate books to students at a school in Qalat, the Zabul province’s capital, according to a statement released by the State Department.

Anne Smedinghoff, a 25-year-old Foreign Service officer, was also killed in the attack, as well as a Department of Defense civilian and Afghan civilians, State Department officials said.

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Four other State Department employees were wounded, including one person who was critically injured, according to the State Department.

Santos was a cavalry scout who joined the Army in February 2007.

This was his second deployment.

Santos was part of the 5th Squadron, 7th Cavalry Regiment, 1st Armor Brigade Combat Team, 3rd Infantry Division at Fort Stewart, Ga. He joined the unit in May 2011.

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