Sri Lanka's freeing of Tamils: step toward redressing rights abuses. For four years, Sri Lanka has been criticized for alleged human-rights violations. Officials deny such charges. But under a recent peace accord, Colombo pledged to free political and other prisoners. Already, hundreds of suspected Tamil rebels have been released. This move may help return the strife-torn island to normal.

As Tamil rebels surrender their weapons, Sri Lankan authorities are freeing suspected rebels from prison under the terms of a recent Indian-brokered peace accord. Monday the Associated Press reported that the government freed 667 Tamils from a prison in southern Sri Lanka. Indian ships took the released prisoners home to eastern and northern Sri Lanka. The government had freed some 300 prisoners Saturday.

Many of the men released Monday claimed they were tortured and abused in detention in various camps. ``Our fingernails were pulled out and we were beaten with pipes and barbed wire,'' said one. He claimed soldiers beat nine Tamils to death in June, when the Tamils went to help three friends purportedly shot by soldiers because the prisoners were late for meals.

During four years of ethnic violence that has claimed some 6,000 lives, Sri Lanka has been the subject of harsh international criticism for alleged widespread violations of human rights. The largest Tamil rebel group, the Liberation Tigers of Tamil Eelam, also has been accused of indiscriminate attacks on Sinhalese and Tamil civilians, as well as attacks on military targets.

The releases and the arms surrender signal hope for a reversal of the violence and political repression in the country once known as an island paradise.

The July, 29, accord between Sri Lankan President Junius Jayewardene and Indian Prime Minister Rajiv Gandhi provides for the release of political and other prisoners held under the Prevention of Terrorism Act and other state-of-emergency laws, as well as prisoners accused, charged, and or convicted under these laws.

If judiciously implemented throughout the country, the impact could be far-reaching, analysts in the region say.

Independent groups and observers estimate that, before the releases, anywhere between 2,500 to 5,000 prisoners were held under the PTA. These figures are almost impossible to verify.

But, in an interview last month, National Security Minister Lalith Athulathmudali denied that Sri Lanka has any ``political prisoners'' - who he defined as nonviolent persons in prison for their political beliefs. He said that thousands of prisoners have been released since 1979 (when the PTA came into effect) and that there are fewer than 2,000 detainees left.

Last month's accord conceded into one unit the main Tamil demand for political autonomy through the merger of the Northern and Eastern Provinces. The mainly Hindu Tamils make up 18 percent of the country's nearly 17 million people. Tamil rebel groups had waged a violent campaign for a separate homeland.

In a report last year, the USState Department said, ``There is substantial credible evidence that both the Tamil militants and the government security forces have been responsible for human rights abuses.''

For the most part, critics accuse the government's security forces and police of human-rights abuses. The accelerated expansion of the security forces - more than double in the last 2 years - and their increasingly Sinhalese composition contributed to human rights suppression, the State Department report said.

Amnesty International, the London-based human rights group, recently urged the Sri Lankan government to investigate the cases of at least 500 persons who reportedly have ``disappeared'' while in the custody of security or paramilitary units in the past 2 years.

It ``feared for the safety of Tamil detainees in Sri Lanka ...,'' Amnesty said. ``Our concern is heightened by our information that government forces have routinely resorted to torture during interrogation. There have been consistent reports of past extrajudicial killings of prisoners by security forces.''

The government has denied the allegations, saying many of the ``disappeared'' have left the country, joined rebel groups, or are in detention under assumed names, which makes them harder to trace.

Despite constitutional guarantees for basic human rights, many lawyers say the guarantees exist only on paper.

``In the same Constitution which guarantees fundamental rights,'' says civil rights lawyer G.G. Ponnambalam, ``you have a provision which says that for reasons of national security or in case of grave crisis, violations of fundamental rights shall not be questioned in a court of law. That one proviso alone knocks out fundamental rights in this country.''

Critics say that both the PTA and 1983 emergency rules give the state sweeping powers that leave much room for abuse. Under the PTA, a person can be detained for a maximum of 18 months without charge or trial. After that, the person can be held indefinitely under emergency regulations, as long as the emergency lasts.

``The PTA is a legal pretext for the so-called due process of law,'' says Bala Tampoe, a Tamil lawyer and labor leader. ``I call it `prevention of trial act' or `postponement of trial act.'''

Tamils have not been the only ones affected. According to Desmond Fernando, a Sinhalese lawyer and head of the country's civil-rights movement, since September 1986 an estimated 600 Sinhalese have been held prisoner in southern Sri Lanka, where the largest prison camps are located. Most of them belong to hard-line, left-wing organizations and are charged with sedition or attempts to overthrow the government by force.

Recourse to high courts or appeal to the government advisory board charged with inquiring into detention cases, many lawyers claim, had proved largely ineffective, time-consuming, and expensive.

It is unclear whether the peace accord ultimately will enable the government to restore citizens' full fundamental rights or whether it can bridge the deep rift between the Sinhalese and Tamils.

But to many battle-weary Sri Lankans, the accord offers the biggest hope yet for the country's return to normalcy.