For a third year running, Amnesty International's annual report on the death penalty notes an alarming surge in the number of executions worldwide—now reaching the highest total since 1989.

At least 1,634 people were executed in 2015, a rise of more than 50 percent over the previous year. Iran, Pakistan and Saudi Arabia were leading the field, responsible for 89 percent of the executions.

Iran executed at least 977 people in 2015—the vast majority for drug-related crimes—compared with 743 in 2014. Those put to death included at least four who were under 18 at the time of the crime—which Amnesty called a violation of international law. Pakistan continued what Amnesty called a "state-sanctioned killing spree" that began when a moratorium on civilian executions was lifted in December 2014. Pakistan sent at least 326 to the gallows last year, the highest annual total Amnesty has recorded for that country. Executions in Saudi Arabia rose by 76 percent, with at least 158 people put to death, Amnesty said. Most were beheaded, with the bodies often displayed in public.

"The rise in executions last year is profoundly disturbing," Salil Shetty, Amnesty's secretary general, told BBC News. "Not for the last 25 years have so many people been put to death by states around the world. In 2015, governments continued relentlessly to deprive people of their lives on the false premise that the death penalty would make us safer."

And this yearly total does not even include China, where Amnesty believes thousands more were executed, but where the records are kept secret.

There was some good news too.

The U.S. carried out 2015's fifth highest number of executions, but the total of 28 was the country's lowest since 1991. Most encouragingly, 2015 marked the first time that a majority of the world's nations have fully abolished the death penalty. Fiji, Madagascar, the Republic of Congo and Suriname all abolished it in 2015, while Mongolia also passed a new criminal code that will take effect later this year. This brings the number of countries worldwide—more than two-thirds—that Amnesty says "are abolitionist in law or practice" to 140.

(Photo Courtesy of Amnesty International)