US drone have hit a facility in Afghanistan on Wednesday, killing 21 people.

The Pakistani intelligence officials said the strike occurred in Afghanistan’s Kunar province, just across the Pakistani border.

The United States made no comment on the strike. There was also no immediate comment from the Afghan government, as well as from the NATO military alliance.

Tensions arose in relations between the United States and Pakistan following US President Donald Trump’s accusations that Pakistan was harboring "terrorists."

Pakistan has vehemently denied the charge and says it has carried out several military operations in the country's tribal regions and elsewhere to kill or arrest militants.

There has been a sharp rise in the number of US drone strikes around the world since Trump took office, according to a report published in December by the Bureau of Investigative Journalism.

The US carries out drone attacks in Yemen and several other Islamic countries, claiming to be targeting al-Qaeda elements. However, local sources say civilians have been the main victims of the attacks.

American technology giant Google has allowed the US Defense Department to utilize its artificial intelligence (AI) technologies in military drone projects, stirring concern among experts who think such cooperation is not ethical.