NAIROBI, Kenya (AP) _ Rebels on Monday rejected Somalia's new premier as window dressing for a brutal regime they seek to topple.

Abdul Kadir, a rebel spokesman in Rome, said the insurgents in Somalia continued fighting in Mogadishu, capital of the Horn of Africa nation.

However, the British Broadcasting Corp., quoting Radio Mogadishu, said a committee of rebels, government representatives and Somali elders had called for a truce beginning at midnight Monday. There was no independent confirmation of the report immediately available.

Earlier in the day, Kadir said the choice of a new premier had done nothing to change the nature of the government.

''We are fighting against the system,'' United Somali Congress spokesman Kadir said in a telephone interview from Rome. ''If the system is still there, a new prime minister has no meaning for us.''

He said his group would be willing to work with the new premier, Umar Arteh Ghaleb, only if the president steps down and Ghaleb accepts a multiparty democracy to replace the ''dictatorial, militaristic system that has ruled our country for 21 years without any respect for human rights.''

The United Somali Congress has been fighting government troops in Mogadishu since Dec. 30. There have been unconfirmed reports of fighting elsewhere.

The rebels seek to end President Mohamed Siad Barre's rule. For months, the president has been shuffling and reshuffling his Cabinet in what opponents say is a vain attempt to put an acceptable face on a repressive administration.

On Sunday, Siad Barre made yet another change, accepting the resignation of a government recently formed under Muhammad Hawadleh Madhar and appointing Ghaleb as the new premier.

Ghaleb, a former foreign minister, is a member of the northern Isaaq clan from which a separate insurgency, the Somali National Movement, draws its force. In the early 1980s, he was charged with treason for criticizing Siad Barre's one-party system and spent six years in prison.

The rebels claim more than 1,500 people have been killed in the civil war. They have appealed to international organizations for food and medicine.

Ethiopian refugee officials say tens of thousands of Somalis have crossed into that neighboring East African nation in recent weeks. Another 1,500 Somalis have fled the fighting by boat and sought refuge in Kenya.

Tens of thousands more are reported to be trying to leave Somalia.

More than 1,000 foreigners were rescued from Mogadishu in separate Italian, French and American operations. Italy was the colonial power.

Siad Barre is a former army commander who seized power in a bloodless 1969 coup. During his rule, he steered Somalia through shifting alliances with the Soviets and the United States.

The United States was his main backer from the late 1970s until a few years ago, when it cut nearly all aid following reports of rights abuses.