Norway’s King Harald V transferred on Monday to a university hospital in Oslo, with the palace saying he was hospitalised for medical examinations and his health was improving.

The 87-year-old monarch returned to Norway aboard a medical aeroplane late on Sunday, a day after he was implanted with a pacemaker while on holiday in Malaysia.

The Norwegian King arrived at Oslo’s Rikshospital in a vehicle marked “intensive ambulance” under police escort.

The palace said he would be on sick leave for two weeks, during which his son, Crown Prince Haakon, would assume the monarch’s duties.

The royal house said that Europe’s oldest reigning monarch was taken to hospital with an infection during a private holiday on the northern resort island of Langkawi.

He underwent surgery at the Sultanah Maliha Hospital on Saturday to implant a temporary pacemaker due to a low heart rate, according to the royal house.

Norwegian media outlets said Harald travelled to Malaysia with his wife, Queen Sonja, to celebrate his 87th birthday.