East Timor, a small territory virtually unknown to most Americans, has attracted the attention of a large number of US congressmen. That concern derives most recently from the impression that Indonesia is covering up human rights abuses in this small former Portuguese colony, invaded by Indonesia in 1975. When Indonesia tightened access to the island territory several months ago, the congressional concern increased.
With a United Nations vote on the Timor issue postponed and access to the island reduced, congressmen who have followed the issue feared that the Indonesians would launch new military operations on the island and cause new civilian casualties among a population which has already suffered heavily.
The Indonesian government denies that any major military operations are under way on East Timor at this time, but diplomats have reported increased military activity in the territory following a ''beefing up'' of the Indonesian forces in East Timor.
Led by Rep. Tony P. Hall, a Democrat from Ohio who has tried to monitor the Timor situation for the past several years, a bipartisan group of 105 members of the House of Representatives, wrote to President Reagan last week expressing concern over reports of a new, large-scale Indonesian military offensive. The House members urged the President to add East Timor to America's foreign policy agenda and use constructive diplomacy to prevent further bloodshed and misery there.
Hall said that the 105 signatures on the letter to Reagan marked a ''high point'' of congressional concern over East Timor. In a 1980 book on Indonesia and the Philippines, State Department official Robert Pringle pointed out that the Timor issue might have faded from the American public view entirely in the mid-1970s had it not been for the efforts of a single congressman, Democrat Donald Fraser of Minnesota, who doggedly questioned the US acquiescence in the Indonesian annexation of East Timor.
The letter commended the Indonesians for ''measurable progress'' made in the reunification of families which have been divided by the conflict in East Timor. But the 105 House members, including nine Republicans, charged that the Timorese ''have barely recovered'' from a famine in the years 1978-80 and a military offensive in 1981, which, the letter asserts, ''caused a reported 2,000 deaths - partially attributable to a forced march of tens of thousands of villagers.''
On Aug. 16 of this year, Indonesia's Armed Forces Commander, Gen. Benny Murdani, stated in an interview with the Indonesian newspaper Sinar Harapan that the Indonesian government would ''crush'' guerrillas of the Fretilin independence movement on East Timor. General Murdani was reported to have said that the situation in the former colony was ''no game any more,'' that there would be ''no mercy,'' and that he could not allow ''this united country to be split apart.''
An Indonesian Embassy official in Washington said that Murdani's statement may have been ''misinterpreted.'' But he acknowledged that some small increase in Indonesian troop strength may have been ordered following an incident which took place on Aug. 8, shortly before Murdani made his statement, in which 16 Indonesians were killed in the south of East Timor by guerrillas, presumably from the Fretilin movement.
The most definitive recent statement on East Timor was made on Nov. 8 at the United Nations by Indonesian Ambassador Ali Alatas. In a letter addressed to the secretary-general, the ambassador stated that no major military offensive was under way and that the ''only security activity'' in the course of this year had been in the area of the Aug. 8 incident.
He charged that ''a tiny band of Fretilin diehards'' carried out an attack on an army engineering unit working on a development project in a remote village. Their sole aim, he said, was ''provoke the security forces'' in order to undermine progress made toward a general amnesty offered by Indonesia.
Much of the letter to President Reagan points to an Indonesians' denial of free access to East Timor by the International Committee of the Red Cross (ICRC).
In his statement, Ambassador Ali Alatas said that the ICRC operations on East Timor had been suspended due to the August incident and Indonesian concern for the safety of ICRC personnel. Western diplomats say the ICRC made its decision to suspend operations in July of this year, well before the August incident, because it could not get access to all the villages where the evaluation of aid requirements would have had to be made.
The ICRC has continued to work on family reunification and tracing operations and sends a physician and nurse to Atauro island off the coast of East Timor to visit the Timorese being held there. But the ICRC has yet to gain access to all prisons on the main island of Timor.
All of this is of interest to the United States, because the US has sent food and medicine to the island through the ICRC and through the Catholic Relief Services (CRS), which runs a development program in a secure area of the island. The congressional letter to President Reagan said that the absence of the ICRC on the main island ''becomes even more disquieting'' in light of a September report by Amnesty International, the London-based human rights organization which states that the Indonesian military has ''engaged systematically and persistently in practices of brutality'' on East Timor.