SEOUL -- The South Korean police planned to mobilize all available riot police across the country on the day when the constitutional court decides whether to impeach President Yoon Suk-yeol over his botched martial law imposition, Yonhap news agency said Wednesday.

The police will issue the highest level of emergency order to deploy about 20,000 riot policemen of 338 units across the country for expected protests and crowd control when the court reaches a conclusion on Yoon's impeachment.

Of the total, about 14,000 riot policemen will be deployed in Seoul, where the constitutional court is located.

On the day of sentencing, detectives will be placed inside the court, and if protesters break into the court, they will be caught red-handed.

Police commandos, as well as paramedics and ambulances, will also be on standby around the court to prepare for emergencies.

Yoon was released on March 8 as the prosecution decided not to appeal against a court's release approval.

The Seoul Central District Court approved the release of the arrested president, accepting Yoon's request to cancel his detention made by his legal team on Feb 4.

Yoon was apprehended in the presidential office on Jan 15 and was indicted under detention on Jan 26 as a suspected ringleader of insurrection, becoming the country's first sitting president to be arrested and prosecuted.

Yoon declared an emergency martial law on the night of Dec 3 last year, but it was revoked by the opposition-led National Assembly hours later.

A motion to impeach Yoon was passed in the National Assembly on Dec 14, and since then the constitutional court held 11 hearings on Yoon's impeachment with its final verdict widely expected to be delivered this week.