Four persons were killed after a roadside bomb struck a vehicle in Afghanistan's eastern Paktia province, a local official said on Sunday. 'The incident occurred on a road in Wazi Zadran district on Saturday evening as a result four people were killed,' the governor of Wazi Zadran district Abdul Ali Zadran told Xinhua. Those killed in the bloody incident, he emphasized had worked as guards to escort the logistic convoys of NATO-led troops in the eastern region. All the victims are Afghans, he added. Taliban militants often target those who work for NATO-led troops and U.S. companies serving in Afghanistan. 