China announced early on Thursday that it had exploded a nuclear bomb in an underground test, its second in three months, a move that can hardly improve its already strained relations with the United States.
A spokesman for the Foreign Ministry, Chen Jian, insisted that the test did not alter China's stance supporting a nuclear test ban, the official New China News Agency reported."China has all along exercised utmost restraint on nuclear testing, and the tests it has conducted are extremely limited in number," the agency quoted Chen as saying.
Military experts have said that China is likely to conduct three more tests before the end of 1996, when a worldwide comprehensive test ban treaty is expected to take effect. China is trying to create lighter, more powerful warheads for its nuclear arsenal, experts have said.
Thursday's test occurred two days after six Greenpeace activists were detained after they held an anti-nuclear protest in Tiananmen Square in the center of Beijing to draw attention to the test, which was expected. The activists were expelled from China on Thursday after intensive questioning by the police.
The tests also occurred during the same week that China conducted a second round of missile tests off the coast of Taiwan, a move widely interpreted as a show of force against the island state after Taiwan's recent efforts to raise its diplomatic status around the world.
"China stands for the complete prohibition and thorough destruction of nuclear weapons," Chen said. "Its posession of a small number of nuclear weapons is solely for the purpose of self-defense and poses no threat to any other country." Western experts estimate China's nuclear arsenal at 450 warheads.
Seismologists in Australia and Sweden said the blast occurred at China's remote desert testing site, Lop Nor, 1,500 miles west of Beijing.
The Australian Seismological Center estimated the blast's magnitude at 5.6. Leif Nordgren at the Research Institute of Swedish National Defense put it at 6.1. The bomb's estimated size ranged from 20 to 200 kilotons.
China has repeatedly promised not to use nuclear weapons first in any confrontation, Chen said. Once the treaty banning nuclear tests is fully negotiated and takes effect, he said, China will stop testing.