Tension Rises in Cambodia Over Coup Plot : Asia: The government closes a newspaper that suggested a Cabinet member was involved. The capital appears quiet but on edge.

The Cambodian government closed one of the nation’s most popular newspapers Friday as tensions continued to swirl throughout the country in the aftermath of an unsuccessful coup.

Phnom Penh appeared quiet but extremely edgy, with the streets deserted at night and a heavy army presence designed to prevent any military movements from the countryside into the city, capital residents said.

The government said it foiled the coup attempt by about 200 soldiers who were intercepted on their way to Phnom Penh early Sunday.

The coup leaders were identified as former Interior Minister Sin Song, who was placed under house arrest, and Prince Norodom Chakrapong, who went into exile in Malaysia after the intervention of his father, King Norodom Sihanouk.

Since Sunday, the government has also arrested Gen. Sin Sen, a senior official of the Interior Ministry, and Tes Thoy, chief of the Police Protective Unit, for taking part in the coup attempt.

The plotters, who allegedly planned to appoint a new government and replace Sihanouk as head of state, reportedly also included a deputy defense minister and several army generals who were said to have taken refuge in Vietnam.

Diplomats in Phnom Penh said it is now clear that the coup attempt had been mounted by hard-line elements of Cambodia’s former Communist Party, which ruled the country with backing from Vietnam from 1979 until U.N.-supervised elections in May, 1993.

Those elections were won by the royalist party headed by Prince Norodom Ranariddh, Sihanouk’s older son, but the threat of civil war forced him into a fragile coalition government with the defeated Communists led by Hun Sen.

Diplomats said that, while the full extent of official involvement in the attempted coup was still murky, the putsch appeared to have had the unintended effect of improving the strained relationship between Ranariddh and Hun Sen, who govern Cambodia as first and second prime ministers. Both men were relieved to see the hard-liners purged, they said.

The costs of the latest instability also became apparent when Singapore Airlines announced it was abandoning plans to form a partnership with the Phnom Penh government to run a new state airline in Cambodia. Singapore Airlines had planned to take a 40% stake in the new carrier, to be called Royal Air Cambodge. Other investors were reported to be putting plans for projects on hold, while aid donors also waited to see how the government crisis wound up before honoring past pledges of assistance.

The jitters in Phnom Penh worsened Friday when the government announced that the Cambodian-language Morning News, one of the nation’s most popular newspapers, had been closed. Its editor, Nguon Nun, was being questioned by police over an article suggesting that Interior Minister Sar Kheng had been involved in the coup plot. Sar Kheng, who has been described as a rising political star, denied he was involved.

The government also banned officials from speaking to reporters about the investigation of the coup plot, in an effort to halt the rumors sweeping the city. Under the constitution adopted after last year’s elections, Cambodia is supposed to have a free press.

The tumult has also been intensified by a vitriolic debate in Parliament, which culminated Wednesday in the passage of a law outlawing the Maoist guerrillas known as the Khmer Rouge, whose rule in the 1970s left more than 1 million Cambodians dead.

The ban on the Khmer Rouge was proposed by Hun Sen after the collapse last month of peace talks, brokered by Sihanouk, between the government and the Khmer Rouge. The Khmer Rouge, which refused to take part in last year’s elections, remains a potent force in Cambodia because of its military strength, and the ban will have no practical effect.

Sihanouk, who is being treated for cancer in Beijing, vehemently opposed the Khmer Rouge ban, so the final bill adopted left the door open to future negotiations with the group. The law includes a six-month amnesty during which group members can turn themselves in.

Some members of the royalist party initially opposed the ban because they feared the law would be used to muzzle government opponents by accusing them of supporting the Khmer Rouge. But they later voted for the bill, averting a major division in the government only days after the coup attempt.

Despite the ban, a number of Cambodia specialists said they expect the Khmer Rouge to play a waiting game to see if the instability in Phnom Penh will lead to so much internal strife that the government can be pushed aside with only minor effort.

The government, meanwhile, has attempted to implicate neighboring Thailand in the coup plot, saying that nine Thai nationals, some in Thai military uniforms, were arrested Sunday during the failed putsch.

Relations with Thailand have deteriorated sharply in recent months after accusations that Thai officials continue to provide shelter and support for the Khmer Rouge; Bangkok has become a bogyman of Cambodian propaganda. In turn, the Thais have tried to block proposals by the United States and Australia to provide military aid to the Cambodians to help fight the Khmer Rouge.