The new military dominated government of Liberia began trials today of former officials and Cabinet ministers under the government of President William Tolbert, who was slain in Saturday's coup.

Charges of treason, corruption and suppression of civil and human rights were lodged against a number of former officials, as Army Sgt. Samuel K. Doe, 28, leader of the coup, lashed out in his first radio address against the Tolbert government.

"Too often have we found public officials dismissed for corrupt practices to be reemployed for higher positions of public trust," Doe charged.

Doe justified his coup, the first in Liberia's history, as a way to restore "dignity, equal opportunity and fair treatment" to the Liberian people.

The Liberian radio also announced that Doe warned that "any soldier caught looting would be shot." The warning came in apparent response to complaints of widespread disorder by elements of the military.

Reports reaching the Ivory Coast indicate that soldiers have been roaming the halls of Monrovia's Ducor Intercontinental Hotel extorting money from the guests at gunpoint. Since the coup, the airport and all overland border posts have been closed. Diplomatic sources said Doe may reopen them by mid-week.

Another band of soldiers was reported to have invaded the Firestone Tire and Rubber Co. residential compound and seized two houses belonging to American citizens. It is not known if anyone was hurt. Firestone, one of Libera's largest employers, with thousands of laborers tending vast plantations of rubber trees, has long been charged with exploitation by the opposition to the former government.

Twenty more senior officials of the Tolbert government were arrested Monday and charged with corruption, news agencies reported from Monrovia.

Among those detained were the direction of Special Security Service, industrial managers, officials of the national airline, two former Cabinet ministers, the deputy managing director of the Liberia Broadcasting Corp., and True Whig Party chairman E. Reginald Townsend.

[Apparently displeased with an incident Sunday in which earlier arrested officials were stripped and paraded nude before jeering crowds, Doe prohibited such displays in the future.]

The coup against Tolbert, 66, was the first in Liberia, a West African country established by freed American slaves in 1847. Tolbert ruled Liberia through his True Whig Party, which represents some 45,000 descendants of the former slaves, called Americao-Liberians. Descendants of those settlers, a close-knit oligarchy, have dominated and sparked resentment among the 1.6 million aboriginal Liberians.

Reaction by African governments to Tolbert's assassination has been mixed.

President Siaka Stevens of neighboring Sierra Leone, who is to be Tolbert's successor this year as chairman of the Organization of African Unity, cancelled a visit to West Germany after the Liberian coup. There were riots in Sierra Leone in March protesting increases in gasoline prices, taxi and bus fares and the recent unrest may have contributed to Stevens' decision to stay home.

Guinea, which flew 200 soldiers to support Tolbert during last year's rice riots in Monrovia, announced it will not "intervene in the domestic politics of Liberia."

Senegal's government newspaper, Le Soleil, today printed an editorial saying that Tolbert's death was symbolic of Africa's ills.

"Tolbert has paid for his lack of imagination and for staying in power too long," the newspaper said. "He has paid for the Americo-Liberians amassing of wealth and this small 3 percent of the population leaned on a government that was profoundly unequal."

The Zambian Sunday Times said the Liberian coup should be "considered another setback" to the African continent. Military men, the paper said, "often are backward politicians and few Africans will be happy to be governed by Army men."

Today, however, the coup began to take on the appearance of having been well thought out and supproted by a broad spectrum of Liberian society. Doe announced a 19-member Cabinet that included three holdovers from Tolbert's government, four members of the formerly banned socialist Progressive People's Party and two leaders of the radical leftist Movement for Justice in Africa (MOJA).

Gabriel Tucker, Kate Bryant and Loseni Dunzo, three young members of Tolbert's Cabinet, were known before the coup to be in quiet sympathy with the leftist opposition and have kept their ministries of public works, health and development.

Gabriel Baccus Matthews, leader of the Progressive Party who was released from prison immediately after the coup, was appointed Foreign Minister. MOJA leader Togba-Nah Tipoteh, a former economics professor at Liberia's univeristy, was named minister of finance and planning.

To shouts of approval and applause, Doe repeated yesterday's announcement that the salaries of soldiers and policement will be raised to a minimum of $250 a month and that of civil servants to $200 a month. The average monthly wage in Liberia is $70.

In recent years, along with several other African counties, Liberia has suffered a sharp economic decline and rising unemployment.

But the small and powerful Americo-Liberian middle class and some indigenous people had grown increasingly richer and ostentatious in displaying their wealth.

Liberia's economy has also been hit hard recently by rising oil costs and an extravagant expenditure of $100 million -- half of its national budget -- to host last summer's Organization of African Unity summit. These factors led to vocal discontent, disturbances and increased opposition to Tolbert's government.

Doe's speech today was delivered on the first anniversary of riots in Monrovia protesting a government proposal to increase the price of rice, Liberia's staple food.