KABUL - An explosion went off in Charikar, the capital city of eastern Afghan province of Parwan on Monday morning with feared casualties, authorities said. ?

"Explosive placed in a car was detonated near the governor office building in Charikar city at around 10 am local time Monday," a provincial official told Xinhua anonymously.

There might be casualties but the police has launched an investigation and details will be released to the media later in the day, he said.

Earlier reports said the nature of the blast was suicide bombing.

The government troops immediately cordoned off the area shortly after the blast in the city, 60 km north of Afghan capital Kabul.

Earlier on Monday, security forces shot and killed a suicide bomber in central Kabul. The attacker tried to assault the country 's National Security Directorate (NDS) or the intelligence agency.

The Taliban-led insurgency has been rampant since the militant group launched annual rebel offensive in April against Afghan government forces and about 100,000 NATO-led troops stationed in the country.

The Taliban urged civilians to stay away from official gatherings, military convoys and centers regarded as the legitimate targets by militants besides warning people not to support the government and foreign troops.