Junius Jayewardene, sworn in today as prime minister following a landslide electoral victory, faces an imminent challenge in the separatist demands of the Tamil minority that is now the main parliamentary opposition.

The Tamils, 1.6 million people concentrated on the north and east of the island, have complained since independence from Britain 29 years ago about discrimination at the hands of the Sinhalese - who make up 70 per cent of the current population of 14 million.

While Jayewardene's United National Party won 139 of the 166 seats in Parliament, the Tamil United Liberation Front won 17 seats, moving past the party of former Prime Minister Sirimaro Bandaranaike. In the crushing defeat, Bandaranaike's Freedom Party won only 8 seats.

[Violence broke out shortly after installation of the new government in parts of Bandaranaike's constituency, the Associated Press reported. Jayewardene ordered in troops and fixed a 9 p.m. to 5 a.m. curfew in those areas.]

The Tamils say that discrimination under Bandaranaike's seven-year rule became so intense that they were able to put aside their own caste and religious differences to form a united party.

Bandaranaike's 1972 constitution had made Sinhalese the national language and Buddhism the state religion. The Tamils have their own 2000-year-old language and are predominantly Hindu. Public sector employment is reserved almost exclusively for Sinhahese, Tamils say.

Under the state of emergency during the last six years, more than 150 Tamil youths were jailed and their accounts of rape, torture and other ill treatment at the hands of the authorities are well documented.

Forty of them, released on bail, fled to India and the son of the Tamil Front leader was granted asylum in Britain.

Revolutionary Tamil youth have intensified a Sialogur with the Marxist liberation front that staged an abortive, bloody coup attempt that triggered the state of emergency in 1971.

While the Tamil Front campaigned on a call for "a war of liberation," its leaders have said they will sit down with Jayewardene at a "roundtable conference" he has proposed Regional autonomy rather than independence is on the conference agenda and many observers feel autonomy is the Tamils' ultimate goal.

Jayewardene's massive - and largely sinhalese - parliamentary majority can cut two ways. It dashed Tamil hopes of playing the kingmaker between his party and Bandaranaike's but it could make the new prime minister confident enough to give in to some Tamil demands. It could also make him feel strong enough to resist them.

Jayewardene has given some signs of moderation on the issue.

He gave his blessing to the marriage of his son, Sinahalese and Buddhist, to a Tamil What's more his party has never relied as heavily on Sinhalese chauvinism as the Freedom Party.

[Bandaranike's son Anura, 28, unexpectedly won the last seat decided in the vote counting, news services reported, and observers said he appeared to be launched on a long political career. His mother also was among the Freedom Party's eight victors.]