The 21st World Congress of International Physicians for the Prevention of Nuclear War concluded Friday in the eastern Kazakh city of Semey with a tribute to the victims of atomic weapons.

In Semey, previously Semipalatinsk, the Soviet Union carried out more than 450 nuclear weapons tests between 1949-1991 and it remains one of the areas most affected by radiation on the planet.

After two days of meetings in Astana, those attending the congress traveled Friday to Semey to take part in a conference of the Nevada-Semey Anti-Nuclear Movement and lay flowers on the tombs of those who died of radiation.

They also visited an exhibition dedicated to the victims of the atomic bombing of Hiroshima in August 1945.

"On Feb. 28, 1989 the Nevada-Semipalatinsk Movement was born," the founder of the organization, Olzhas Suleimenov, recalled, adding that it was created as a result of alarming medical reports indicating an unprecedented mortality rate.

Suleimenov and his colleagues included "Nevada" in the name as a nod to similar movements in the United States that sought to close the Nevada Test Site.

It was Kazakhstan's now-President Nursultan Nazarbayev who dared to suggest before the Central Committee of the Soviet Communist Party that the Semipalatinsk nuclear polygon should be closed, which he finally achieved.

Another activist in the movement, Karipbek Kuyukov, a Kazakh painter born without hands due to radiation damage, told Efe about the first steps of the Nevada-Semipalatinsk group.

"The last 25 years of my life have been a battle. When I joined the movement, I remember that in those days when neither the Internet nor mobile phones existed, we collected signatures on sheets of paper from every region," he said.

He said that more than 2 million Kazakhs signed the petition to close the nuclear polygon at that time.

On Aug. 14, Semey was the starting point of a bicycle trek sponsored by a group of medical students from eight countries seeking to attract the attention of the international community to the plight of Kazakhstan's radiation victims. EFE