The U.S. Supreme Court on Monday cleared the way for federal executions to resume following a 17-year pause after it denied to hear a challenge from death row prisoners over the Trump administration's lethal injection protocol.

"At a moment when people around the country are demanding justice, equality, and accountability, clearing the way for federal executions is a mistake," tweeted the ACLU. 

The order (pdf) from the high court indicates that liberal Justices Ruth Bader Ginsburg and Sonia Sotomayor would have heard the challenge.

U.S. Attorney General William Barr last year directed the Bureau of Prisons to resume capital punishment, with pentobarbital as the sole drug for the lethal injections.

Author and anti-death penalty activist Sister Helen Prejean said court's decision "means that the federal government will likely execute four people beginning month using an untested lethal injection protocol during a global pandemic without any real oversight from the Supreme Court. All of this is against the wishes of at least one victims' family."

Three federal executions are currently scheduled for July and one for August. All the state-sanctioned killings are scheduled to take place at the Federal Correctional Complex in Terre Haute, Indiana.

The high court's decision doesn't mark the end of the road for the inmates' legal challeges, as they're "separately asking a federal judge in Washington to impose a new delay on their executions over other legal issues that have yet to be resolved," as the Associated Press reported.

The last federal execution took place in 2003. And, according to California Innocence Project director Justin Brooks, it should be the last.

"The Supreme Court must eventually rise above the fear driven politics in the USA and bring us in line with the rest of the civilized world when it comes to the #DeathPenalty," Brooks tweeted. "It is a human rights violation."