Afghan policemen stand guard at the site of blast in Ghazni city, Afghanistan, on May 29, 2013. Earlier on Wednesday, four people, including three school girls, were wounded when two back-to-back Improvised Explosive Devices ( IEDs) went off near a girl school in Ghazni city, the provincial capital of eastern Ghazni province 120 km south of capital Kabul. (Xinhua/Rahmat)