Israeli intelligence officials have confirmed that a major explosion has rocked an Iranian nuclear facility, according to a report Monday in The Times of London.

The British daily cited officials in Tel Aviv who said the blast occurred last week, as originally reported on the website wnd.com.

Iran is not believed to have evacuated the area surrounding the Fordo plant, according to the same Israeli sources, who said that an investigation into the blast was ongoing.

“We are still in the preliminary stages of understanding what happened and how significant it is,” one Israeli official told the London Times. He did not know if the explosion was “sabotage or accident” and refused to comment on reports that Israeli aircraft were seen near Fordo at the time of the blast.

On Sunday, two senior Iranian officials dismissed reports of the explosion.

Deputy head of the Iranian Atomic Energy Agency Seyyed Shamseddin Barbroudi said there had been no explosion at the Fordo facility whatsoever, according to the official Islamic Republic News Agency.

The chairman of the Iranian parliament’s Committee for Foreign Policy and National Security, Alaeddin Boroujerdi, referred to rumors of the blast as “Western-made propaganda” and said they were “baseless lies” meant to impact ongoing talks on Iran’s nuclear program, reported IRNA.

The original wnd.com report published Friday claimed that a blast deep within Fordo last Monday “destroyed much of the installation and trapped about 240 personnel deep underground,” citing information from former intelligence officer Hamidreza Zakeri, who it said used to work with the Islamic regime’s Ministry of Intelligence and National Security.

The article claimed the blast “shook facilities within a radius of three miles,” that Iranian security forces had “enforced a no-traffic radius of 15 miles,” that the Tehran-Qom highway was shut down for several hours after the blast, and that, “as of Wednesday afternoon, rescue workers had failed to reach the trapped personnel.” It said US officials were aware of the reported blast.

Asked about the incident on Sunday, Home Front Defense Minister Avi Dichter, a former head of Israel’s Shin Bet security service, said, “Any explosion in Iran that doesn’t hurt people but hurts its assets is welcome.” Dichter was acting defense minister Sunday, in the absence of Ehud Barak.

Iran insists its nuclear program is for peaceful purposes, but that claim has been rejected by much of the international community. The Islamic Republic’s consistent refusal to allow international inspectors into the Fordo nuclear facility has frustrated Western powers and officials at the International Atomic Energy Agency.