A bomb blast was reported in Afghanistan's capital city of Kabul on Monday near the labour ministry office.
According to local media, a magnetic bomb was placed on a police ranger truck.
The US Embassy in Kabul sent out an emergency message to Americans living in Afghanistan to be on guard as it claimed to have has received 'credible reports of an imminent attack in the next 48 hours' in the capital. It also warned US citizens against travelling to the country.
The Taliban has launched deadly attacks in Kabul in recent months, striking NATO troops and government offices in suicide bombings.