A U.S. drone strike killed at least 17 people in Pakistan's tribal region on Wednesday, Reuters reports.

Taliban commanders and security officials told Reuters that the strike mostly killed fighters for the Haqqani network.

But Reuters also reports this (emphasis ours):

Many were wounded in the attack, local tribesman Kaleemullah Dawar said, but rescuers delayed for fear of falling victim to a second attack, a common tactic with drone strikes.

That tactic is known as the "double tap," which bombs multiple targets in relatively quick succession — meaning that the second strike often hits first responders.

NYU Student Josh Begley revealed the trend while tweeting every U.S. drone strike since 2002.

Last year a study by the NYU School of Law and Stanford Law School detailed the U.S. use of the double tap, providing first-hand accounts of its devastating effect on rescuers and humanitarian workers.

In 2007 the FBI said the tactic as commonly used by terrorist organizations such as Hamas.

Last June the UN special rapporteur on extrajudicial killings Christof Heyns said he considers secondary strikes to be "war crimes."

And the NYU/Stanford report stated: "As international law experts have noted, intentional strikes on first responders may constitute war crimes."

The fact that it is now normalized as a common tactic of the U.S. drone war is stunning.

Furthermore, Spencer Ackerman of The Guardian reports that a recent study conducted by a U.S. military adviser found that over the course of a year that U.S. drone strikes in Afghanistan caused 10 times more civilian casualties than strikes by manned fighter aircraft.

That finding contradicts the common drone defense that the robotic planes are more precise than manned planes.

According to the study, drone strikes in Afghanistan were "an order of magnitude more likely to result in civilian casualties per engagement" than manned bombing runs.

Ackerman notes that the study appears to undermine a claim made by President Obama in May when he said "conventional airpower or missiles are far less precise than drones, and likely to cause more civilian casualties and local outrage."

After a decade of drone warfare, it's becoming clear that the U.S. has set a dangerous precedent for the rest of the world.