Israeli soldiers set off an explosion Tuesday in the building adjacent to Yasser Arafat's office, according to aides to the Palestinian leader who were inside the compound.

Israel's army said the blast, and another earlier Tuesday inside the compound, were controlled explosions to blow up weapons found inside buildings.

The blast adjacent to Arafat's office was in a building that had been part of the Palestinian prison at the compound, said Tawfik Tirawi, head of Palestinian intelligence in the West Bank. He accused Israel of wanting to destroy the wall between the prison and Arafat's office so they could easily enter.

"This building shared a wall with the president's office," Tirawi said. "If I'm reading the Israelis well, they want to destroy this wall so that they can easily enter the office."

The earlier explosion in the compound was farther from Arafat's office. It was in a building once used as sleeping quarters for Palestinian security men, but has been vacant during the siege, Palestinian officials said.

The Israeli army said its soldiers carried out controlled explosions of grenades found in the compound, the first a stash of five and the second of six.