The U.N. nuclear watchdog agency has information Iran may be engaging in a new nuclear cover-up near a military facility outside Tehran, diplomats said Thursday as the agency's board prepared to rebuke Iran for hindering an international probe.

The agency was looking at intelligence that Iran was razing parts of a restricted area next to a military complex in a Tehran suburb, the diplomats said on condition of anonymity.

Satellite photos showed that several buildings had been destroyed and topsoil had been removed at Lavizan Shiyan, one diplomat said.

The diplomat said that to his knowledge the International Atomic Energy Agency (search) had not visited that site, although agency officials told the Iranians they were concerned about the unexplained activities.

"It's vanishing now, so they need to look at it," said the diplomat, adding that the agency also was focusing on other sites. The diplomat did not elaborate.

The IAEA is investigating nearly two decades of covert nuclear activity by Iran. Tehran maintains its program is meant to generate electricity, but the United States claims it is a weapons program.

President Bush has labeled Iran part of an "axis of evil" with North Korea and prewar Iraq.

The diplomats spoke to The Associated Press as delegates to the IAEA's board of governors agreed on the text of a toughly worded Iran resolution Friday.

The text expresses "strong concern" and "deplores" foot-dragging by Iran on revealing its nuclear secrets but contains no "trigger mechanism" — a clause sought by Washington that could send the Iran case to the U.N. Security Council for violating the Nuclear Nonproliferation Treaty (search).

But a Western diplomat familiar with the U.S. position said the Americans were content because they "feel this ... helps tee (Iran) up for Security Council action" at the next board meeting in September.

He did not elaborate. But another diplomat said Washington was waiting for the IAEA to discover new incriminating evidence, including signs that Iran was trying to hide past covert nuclear activity at Lavizan Shiyan and test results of enriched uranium samples taken from military sites.

The diplomat suggested the IAEA had access to American intelligence concerning the Lavizan Shiyan site, but agency officials refused to comment.

Agreement on the text of the censure came despite Iranian efforts to substantially tone it down, including tactics that forced IAEA chief Mohamed ElBaradei (search) on Thursday to admit a mistake in a report criticizing Tehran for repeated lack of cooperation with the agency probe.

Iran maintains it never had a fully functioning uranium enrichment program but was interested in the process to generate electricity. Enrichment can be used to produce power or bombs.

Since the IAEA started its probe a year ago, Iran has suspended what it says were experimental enrichment activities but has not scrapped them altogether. Tehran suggested Wednesday that the program could be reactivated if the IAEA resolution is too harsh.

Iran maintains it has a right under the nuclear treaty to pursue a peaceful atomic program, including enrichment.

The IAEA has found traces of enriched uranium, including weapons-grade samples, at several sites in Iran. Tehran says those minute finds were not produced domestically but rather were inadvertently imported when it made purchases through the nuclear black market — an assertion the agency has not yet proven.

ElBaradei admitted his report the board incorrectly stated that Iran did not report the purchase of 150 magnets for P-2 centrifuges.

Iran submitted an audio tape recording an IAEA inspector being informed about the purchase. IAEA officials said the mistake was made because Iran did not report the purchase in writing.

ElBaradei said Iran also asked a black market supplier about the possibility of buying "100,000" magnets.

"How would that square with an R-and-D (research-and-development) program?" he asked.

The report also said Iran inquired about buying thousands of such magnets on the black market — substantially more than Tehran needed for what it said was a research program.

Iran's chief delegate, Hossein Mousavian, said the mistake showed "Iranian information has been full, with no contradictory ... information."