Afghan troops, assisted by Canadian military forces, focused on villages in the area of Kandahar province where 400 rebels escaped from jail last week, CNN reported.
Thousands of soldiers and police officers began moving into the Arghandab district Wednesday for the operation that's expected to last three days, said Afghan Defense Ministry spokesman Gen. Zahir Azimi.
NATO and Afghan forces dropped leaflets that warned residents to stay inside their homes if fighting broke out nearby.
Meanwhile, the British Defense Ministry reported four British soldiers were killed in another part of southern Afghanistan Tuesday, The New York Times reported.
"The soldiers were taking part in a deliberate operation east of Lashkar Gah when the vehicle in which they were traveling was caught in an explosion," the Defense Ministry said in a statement issued in London.