An Afghan official said that at least 400 inmates escaped from the main prison in Kandahar through an overnight tunnel, Monday. Kandahar is in the southern part of Afghanistan. Most of the escaped prisoners are Taliban insurgents.

Kandahar is the focus of international effort to defeat insurgency, and the colossal jailbreak in the city is a reminder that Afghanistan can still easily be thwarted in the south. This is despite the arrival of international funding, troops, and advisers.

The escape took place even after the 1,200-inmate Sarposa Prison tightened and upgraded their security procedures. The Afghan government worked hard to improve security in their prison cells after the 2008 Taliban attack which caused the escape of 900 prisoners.

On Sunday night, an average of 476 prisoners escaped thru a dug tunnel between the prison and the outside world. They then disappeared into the city even before prison officials found out they were missing. Ghulam Dastagir Mayar, prison supervisor, said that the majority of the missing prisoners are Taliban militants.

Zabiullah Mujahid, Taliban spokesman, said that allies of the imprisoned insurgents dug the tunnel over five months, working under the prying eyes of the government. On Sunday night, the tunnel reached prison cells, freeing the inmates. The inmates were led by three prisoners who were informed of the plan months back.

The Sunday’s escape is more thought off and less brutal than the 2008 attack wherein two suicide bombers crashed a tanker truck laden with explosives straight to the prison gate.