Photographs and a floor plan of the Belgian prime minister's office were found on a discarded laptop that belonged to one of the suspects linked to last week's terror attacks in Brussels, The New York Times and several Belgian news outlets reported on Wednesday.
Belgian newspaper De Morgen reported that the prime minister, Charles Michel, was made aware of the discovery last week. Additional security measures are reportedly in effect for his office building, and visitors are being more tightly controlled.
Belgium has apparently asked the US to help authorities analyze and decrypt information on the laptop, which was discovered in a trash can during a raid on a house in the Schaerbeek section of Brussels shortly after the attacks.
The laptop also contained a suicide note believed to have been written by one of the bombers, Belgian national Ibrahim El Bakraoui. He reportedly wrote in French that he was in "a bad situation" and that, if he did not act immediately, he would end up in a prison cell "like him."
The note likely alluded to the arrest of Salah Abdeslam, a suspect in November's Paris attacks who was detained in Brussels last week after four months of evading capture. Abdeslam is believed to have played a role in organizing and planning the Brussels attacks before his arrest, authorities have said.
The Belgian prime minister was not the only high-value target the Brussels attackers had their eye on. They reportedly were believed to have been planning an attack on a Belgian nuclear plant, but changed their plans following Abdeslam's arrest.
A raid in December turned up a video with 10 hours of footage from a camera hidden in front of a nuclear official's house. Experts believe that the attackers had planned to blackmail the official to gain access to the facility in order to make a "dirty bomb" — an improvised nuclear device that could spread radioactive material across a wide area, NBC News reported last week.
Police also found 15 kilograms of explosives of the TATP type, 150 liters of acetone, detonators full of nails and screws, plastic bags, ventilators, and several other bomb-making materials during their raids last Tuesday, following explosions at Brussels' Zaventem Airport and Maelbeek metro station that killed 35 people and wounded at least 300 more.
The man on the left of the CCTV image is Najim Laachraoui, the suspected bomb-maker involved in November's Paris attacks who detonated a suicide vest along with Ibrahim El Bakraoui the airport last Tuesday.
The police have not yet identified their third suspect — the man wearing a light jacket and hat in a photo released by Belgian authorities — but say he is still on the run. His bag apparently contained the largest of the three explosives that were brought to the airport. That explosive did not go off with the other two and was detonated in a controlled explosion by the police.