SEOUL  -- South Korea's National Office of Investigation (NOI) said Tuesday that five key police and military officials, including the police chief, have been banned from leaving the country amid an ongoing investigation into President Yoon Suk-yeol's martial law declaration.

The NOI said its special investigation team imposed an overseas travel ban on Cho Ji-ho, commissioner general of the Korean National Police Agency, Kim Bong-sik, head of the Seoul Metropolitan Police Agency, and Mok Hyun-tae, head of the National Assembly Police Guards.

The travel ban was enforced by the Ministry of Justice at 8 pm local time Monday, the NOI added, noting that the three were allegedly involved in controlling access to the National Assembly during the martial law enforcement on Dec 3.

Meanwhile, Lee Jin-woo, chief of the Capital Defense Command, and Kwak Jong-geun, former chief of the Army Special Warfare Command, have also been placed under a travel ban in connection with the same investigation.

The NOI said it has asked the defense ministry and several military commands to submit data on the deployment of troops related to the martial law decree.