FACTBOX-Security developments in Afghanistan, Aug 25

(For more on Afghanistan, click on [ID:nAFPAK])

Aug 25 (Reuters) - Following are security developments in Afghanistan at 1130 GMT on Tuesday:

* Denotes new or updated items.

* SOUTHERN AFGHANISTAN - Four U.S. servicemen were killed in an explosion on Tuesday in an area of southern Afghanistan, NATO said.

PAKTIKA - A roadside bomb killed four Afghan civilians working for a construction company in Yousef Khil district, Paktika province, the ministry of interior said in a statement.

LOGAR - Afghan troops arrested a key Taliban bomb maker and found a cache of 300 improvised explosive devices in Logar province to the south of Kabul, the defence ministry said.