At least four countries that had not used the death penalty in some time — India, Japan, Pakistan and Gambia — resumed doing so last year, the rights organization Amnesty International says in its annual compilation of capital punishment trends.

Amnesty, the London-based group that has made abolition of the death penalty one of its signature causes, also says the number of executions in Iraq nearly doubled in 2012 compared with a year earlier, which it characterized as “an alarming escalation.”

Nonetheless, its yearly review, released early Wednesday in London, said the overall shift away from death sentences and executions continued in 2012.

“In many parts of the world, executions are becoming a thing of the past, ” Salil Shetty, secretary general of the organization, said in a statement. Amnesty said only 21 countries were recorded as having carried out executions in 2012, the same as in 2011, but down from 28 countries a decade earlier.

It said at least 682 executions were known to have been carried out worldwide in 2012, two more than 2011, and at least 1,722 death sentences were imposed in 58 countries, compared with 1,923 imposed in 63 countries the year before.

“Only one in 10 countries in the world carries out executions,” Mr. Shetty said. “Their leaders should ask themselves why they are still applying a cruel and inhumane punishment that the rest of the world is leaving behind.”

Amnesty also pointed out that its compilation excluded what it said were the thousands of executions it believes were carried out in China, where the number of capital punishment cases is kept secret. The organization said it still believed China remained the world’s top executioner.

Besides China, the top executors in 2012, Amnesty said, were Iran with 314, Iraq with 129, Saudi Arabia with 79 and the United States with 43. The report also noted that only nine American states executed prisoners in 2012, compared with 13 the year before, and that in April, Connecticut became the 17th state to abolish the death penalty.