Image copyright Getty Images Image caption US drone strikes have been used to fight extremists in countries such as Yemen

President Donald Trump has revoked a policy set by his predecessor requiring US intelligence officials to publish the number of civilians killed in drone strikes outside of war zones.

The 2016 executive order was brought in by then-President Barack Obama, who was under pressure to be more transparent.

Since the 9/11 terror attack, drone strikes have been increasingly used against terror and military targets.

The Trump administration said the rule was "superfluous" and distracting.

The order applied to the CIA, which has carried out drone strikes in countries such as Afghanistan, Pakistan, and Somalia.

"This action eliminates superfluous reporting requirements, requirements that do not improve government transparency, but rather distract our intelligence professionals from their primary mission," an official said.

What was the rule?

It required the head of the CIA to release annual summaries of US drone strikes and assess how many died as a result.

Mr Trump's executive order does not overturn reporting requirements on civilian deaths set for the military by Congress.

There have been 2,243 drone strikes in the first two years of the Trump presidency, compared with 1,878 in Mr Obama's eight years in office, according to the Bureau of Investigative Journalism, a UK-based think tank.

An uptick in deaths

Tara McKelvey, BBC News, White House Reporter

Human-rights activists complained about the drone programme under the Obama administration, saying the operations were overly secretive and hid the fact that civilians were sometimes killed in the strikes.

President Obama responded by saying that strikes were carried out in a precise manner - and that intelligence officials would release data on civilians who were accidentally killed in the strikes that occurred outside of war zones. President Trump has built on the existing programme and made it even more ambitious.

During Mr Obama's eight years in office, 1,878 drone strikes were carried out, according to researchers. Since Mr Trump was elected in 2016, there have been 2,243 drone strikes. The Republican president has also made some of the operations, the ones outside of war zones, more secretive. As a result, things have different today: under Mr Trump, there are more drone strikes - and less transparency.

What is the reaction?

Lawmakers and rights groups have criticised Mr Trump's decision, saying it could allow the CIA to conduct drone strikes without accountability.

"The Trump administration's action is an unnecessary and dangerous step backwards on transparency and accountability for the use of lethal force, and the civilian casualties they cause," Rita Siemion of Human Rights First told AFP news agency.

Representative Adam Schiff, a Democrat who chairs Congress's intelligence committee, called the requirement issued by Obama "an important measure of transparency," and said "there is simply no justification" for cancelling it.