All eyes were on Seoul's presidential Blue House Saturday as South Koreans awaited ex-president Park Geun-Hye's reaction to her impeachment and preparations to move into her private residence.

Election authorities expressed concern over growing tensions in the lead-up to polls to elect a new president, while newspaper editorials called for an end to ongoing street protests.

A third person died Saturday in hospital after he lost consciousness the day before in a clash between pro-Park supporters and riot police, near the Constitutional Court which confirmed Park's impeachment.

The main opposition Democratic Party urged Park to accept the court ruling, accusing her of behaving as if she were rejecting the decision reached unanimously by the court's eight judges.

News reports said Park was watching television alone in her private presidential room Friday when the country's highest court announced her dismissal live on air.

An incredulous Park immediately phoned her aides to confirm the verdict, the Chosun Ilbo daily said.

Her aides told the newspaper she had no immediate plans to issue a statement on the court decision or her future course of action.

"The president was apparently stunned at the ruling. She looked dejected," an unidentified aide was quoted as saying.

"She wants to keep to herself for a while," he added.

Park will leave the Blue House only after her private house in prosperous southern Seoul is repaired and cleaned to accommodate her and her security detail.

TV footage showed materials being unloaded from a small truck parked outside the two-storey house.

Police said more than 200 officers were deployed around the area.

Park is obliged to move out of the presidential palace, where she has been holed up for more than 90 days after the National Assembly voted for her impeachment in October.

The court's verdict upholding her impeachment immediately stripped her of all powers and privileges, except for her security.

Park was found to have broken the law by allowing her friend Choi Soon-Sil to meddle in state affairs, and breached rules on public servants' activities.

The ruling also removed her presidential immunity to criminal indictment.

Park has already been named a criminal suspect, accused of bribery for offering policy favours to firms that benefited Choi.

For months she has refused to make herself available for questioning by prosecutors probing the scandal.

But that may no longer be an option once she leaves the Blue House, when she could face formal arrest if she refuses a summons.

South Korea's top election official Kim Yong-Deok said in a statement there was "growing concern" over the highly charged atmosphere ahead of an election which must take place no later than on May 9.

"The vote must serve as a chance to overcome divisions and conflicts and achieve national unity and harmony," he said in a speech aired live on TV.

Yonhap news agency said the third victim was a 74-year-old man who collapsed during a demonstration near the Constitutional Court.

A demonstrator died the day before after being hit on the head by a speaker that fell from the top of a police bus when a protestor commandeered the vehicle and drove it into police barricades.

Police arrested the 60-year-old protestor and several others for violent behavior.

Pro-Park protestors assaulted photographers and TV crew members, leaving them with cuts and bruises.

Police issued a statement vowing to track down and punish unruly protestors as pro-Park supporters planned to hold fresh demonstrations near the Constitutional Court and in the city centre on Saturday afternoon. (AFP)