Thousands of anti-impeachment demonstrators streamed into the streets on Sunday, as North Korea asked that economic talks with the South be switched to the North because of "uncertainty" over the impeachment of President Roh Moo-hyun (search).

Dubbed by some as a "coup without guns," the opposition-controlled parliament stunned the nation on Friday by impeaching Roh on charges of violating election rules and incompetence.

Rival North Korea (search— in a veiled reference to the historic move to oust Roh — meanwhile expressed concern over a "very unstable" political situation and "unprecedented confusion" in the South.

Pyongyang requested that a round of inter-Korean economic talks, scheduled to begin Monday in the South, be switched to the Northern city of Kaesong, according to an official North Korean radio broadcast monitored by South Korea's (searchYonhap news agency.

Prime Minister Goh Kun (searchhas assumed executive powers and the Constitutional Court will rule whether the impeachment of Roh was constitutional. It will meet Thursday to review the case.

Preparing for the country's first impeachment trial, Roh tapped a former adviser on civil affairs, Moon Jae-in, to put together a legal team to defend the president, Roh spokesman Yoon Tae-young said.

Opinion polls show that about seven in 10 South Koreans oppose the impeachment.

On Saturday night, about 50,000 angry demonstrators streamed into the streets of downtown Seoul, singing songs, waving candles and holding placards reading: "Defend Democracy!"

The movement against Roh's impeachment has found support not only among his political backers but also from civic groups that have criticized alleged corruption in Roh's administration, his decision to send troops to Iraq and his recent tussle with authorities over illegal campaign funds ahead of next month's parliamentary elections.

In the run-up to the impeachment, one Roh supporter set himself on fire and another tried to drive his car up the National Assembly steps and into the building.

But protests have been mostly peaceful.

Trying to quell concerns of a national division over the impeachment, the pro-government Uri Party vowed not to organize or lead any street protests that could further fuel political unrest.

"This incident is clearly unconstitutional and illegal, but we will not stage any street demonstrations," Chung told business leaders Sunday.

Chung also urged the Constitutional Court to issue a swift ruling on the impeachment.

"It is completely up to the Constitutional Court whether this national emergency will last a week, a month or three months," he said.

The People's Solidarity for Participatory Democracy, a civic group that sponsored Saturday's protest, called for nightly rallies in downtown Seoul to oppose what it calls the "oppression by the majority under the pretext of law."

The group is often critical of Roh, but says the opposition has gone too far.

The Grand National and Millennium Democratic parties accuse Roh of breaking election laws by stumping for the Uri Party in the upcoming April 15 parliamentary poll. Roh doesn't belong to the Uri party but has said he wants to join.

Government officials are not allowed to campaign for political parties under South Korean law, but the National Elections Commission ruled Roh's infraction was minor, not warranting criminal charges. All the same, the opposition have demanded an apology.