A water tanker loaded with explosives blew up amid a deafening roar near the German Embassy here on Wednesday, killing at least 80 people, wounding around 350 and causing widespread destruction, authorities said. No group has claimed responsibility for the bombing that hit in a highly secure diplomatic area of the Afghan capital.

Among the dead was an Afghan journalist from Tolo News, media outlets reported.

The attack was the second massive bombing in Kabul this month.

Shocked residents soaked in blood stumbled in the streets before being taken to hospitals.

The Taliban - now in the midst of their annual "spring offensive" - denied they were involved, while strongly condemning the blast.

No one has claimed responsibility for the bombing yet, but Afghanistan has been losing ground in its battle against extremists.

The commander of U.S. forces in Afghanistan, General John Nicholson, told a congressional hearing this year that he needed several thousand more troops to help Afghan forces break a "stalemate" with the Taliban. Indian staff at the embassy are safe, reports said. "However, the blast was very large and nearby buildings including our own building have considerable damage in terms of broken glass and shattered windows and blown doors etc", he said.

Afghan President Ashraf Ghani and countries like Germany, Iran, Egypt, China, India, Malaysia, Pakistan and Qatar condemned the attack. "Our thoughts are with the families of the deceased & prayers with the injured". "Two Japanese embassy staffers were mildly injured, suffering cuts", a foreign ministry official in Tokyo told AFP.

France, Turkey, the United Arab Emirates and Bulgaria similarly reported damage to their embassies, while India and Pakistan joined in worldwide condemnation of the blast. Bulgaria said its mission had been damaged and its staff evacuated.

Pentagon chief Jim Mattis has warned of "another tough year" for both foreign troops and local forces in Afghanistan.

This is a developing story -- check back soon for more reporting.

The US has about 8,400 troops in Afghanistan.

It was one of the worst attacks Kabul had seen since the drawdown of foreign forces from the country at the end of 2014.

"I have been to many attacks, taken wounded people out of many blast sites, but I can say I have ever seen such a terrible attack as I saw this morning", ambulance driver Alef Ahmadzai told The Associated Press.