A laptop used by one of the Brussels bombers contained images of the Belgian prime minister's home and office, an official said Wednesday, heightening fears after last week's attacks on the airport and subway system.

A government official, who spoke on condition of anonymity because the investigation is ongoing, said that "it is alarming that they were apparently scouting the terrain" around the lush Royal Park where both his office, "Le 16," and his Lambermont residence are located.

Security around Prime Minister Charles Michel has increased since the Nov. 13 attacks in Paris and in Brussels last week. Michel also has had several unspecified death threats over the past years, the official said.

A laptop found near the hideout of the suspects of the March 22 airport bombing first gained notoriety because it contained a sort of will of suicide bomber Ibrahim El Bakraoui, in which he spoke of being "in a haste" and "no longer know what to do."

The computer was also "full of stuff" on many locations around Brussels in information garnered from the Internet, said an official linked to the investigation.

The official, who asked not to be identified because the investigation is ongoing, said that at the moment there were "absolutely no" specific indications that Michel was under threat from the attackers.

The report was first published by De Tijd and L'Echo newspapers.

In propaganda material distributed Tuesday, the Islamic State group described the Brussels attacks as part of "a war against all their tyrants and pagans; a war against secularism." The material showed a cropped still of surveillance footage showing the two airport bombers. The attacker who escaped with his life, wearing a dark hat, was cropped out.

"Its most important results are that it showed the fragility of the security systems of the European states that claim they are the strongest in the world, and this was through the type of operation, its timing, its place, and the circumstances surrounding it, and the nature of those who executed it," the material said, according to a translation Wednesday by the SITE Intelligence Group.

In all, 32 people died in the attacks on Brussels international airport and the Maelbeek subway station and 87 remained in hospital. Three attackers were killed when their bombs exploded and police are looking for at least one more suspect.