Defiant in the face of international condemnation, France said it conducted a third underground nuclear test at its blast site in the South Pacific on Friday afternoon.

The blast took place beneath Mururoa Atoll in French Polynesia, the Defense Ministry said Friday night. It said the blast, which occurred at 1 p.m. local time, was about 60 kilotons, the equivalent of 60,000 tons of TNT.

“This test was necessary to guarantee in the future the security and reliability of our arms,” the ministry said in a short statement.

Governments and environmental groups worldwide have roundly condemned France for breaking a 1992 moratorium on nuclear tests with a Sept. 5 blast beneath the atoll, about 750 miles southeast of Tahiti. Friday’s test was France’s 207th since 1960.

The first test measured less than 20 kilotons, slightly larger than the bomb dropped on Hiroshima in 1945. A second, much more powerful blast of about 110 kilotons was set off Oct. 2 beneath neighboring Fangataufa Atoll.

The environmental group Greenpeace expressed its outrage.

“The French thumb their nose yet again at huge world opinion,” said Glyn Walters, the environmental group’s spokesman in Papeete, the capital of French Polynesia.

Walters said Chirac’s approval ratings, plummeting in part because of the unpopularity of the tests, would take another hit.

“We have seen his popularity going down with every new test. And we strongly believe that he will have to reduce the tests further, and we hope that he will,” he said.

Rioting broke out in Papeete when the first bomb was detonated in September. There were no immediate reports of trouble in the city following the latest test.