Updated June 24 at 13:00 Tehran time - An Iranian news site close to security services said around 1:00 pm Tehran time that authorities had thwarted a "sabotage attack" on the country's civilian nuclear program, without providing further information. Initially, one Iranian news website and social media reports said a drone attack was the cause of the incident.

Nournews, the website close to Iran's Supreme National Security Council, first reported that the attack was foiled "before causing any damage to the building." It said the case was "under investigation."

When asked for comment by AP, an Iranian official referred to the Nournews report. As of Thrusday, Iranian officials made no further comments.

The Iranian Labour News Agency (ILNA) said a drone attack targeted the facilities of Barakat Pharmaceutical Foundation and described it as "an attack by Iran's enemies" but did not offer any further details, except saying a quadcopter drone was involved. The agency later removed the page from its website. However, social media users said the pharmaceutical company was near a nuclear facility.

Social media posts spoke of gunfire around Karaj, without specifying the time. They also reported the large presence of security forces.

A small local news website quoted an unnamed Iranian army anti-aircraft systems officer as saying that the sabotage did not involve any drone and army units were not involved in repeling any attack.

Iran's semi-official ISNA news agency said the building was located near Karaj city, some 40 kilometers (25 miles) west the capital of Tehran. Iran's Atomic Energy Organization describes the Karaj city facility as a center founded in 1974 that deals with the improvement of the "quality of soil, water, agricultural and livestock production using nuclear technology."

The website of state-owned IRAN newspaper published the same report without offering the location or other details. Iranian state TV carried the report on its news ticker.

The New York Times reported later on Wednesday that the targeted "building was one of Iran’s main manufacturing centers for the production of the centrifuges used at the country’s two nuclear facilities, Fordow and Natanz, according to an Iranian familiar with the attack and to a senior intelligence official." The paper also said that the attack was conducted by a quacopter drone.

The Jerusalem Post said quoted unnamed sources that the attack caused major damage to one of the buildings of the Atomic Energy Organization, but added that it cannot independently verify the information.

The report comes after a series of suspected sabotage attacks targeting Iran's nuclear program in recent months. In April, Iran's underground Natanz nuclear facility experienced a mysterious blackout that damaged some of its centrifuges.

Iran described the blackout as an act of "nuclear terrorism," raising regional tensions as world powers and Tehran negotiated a return to its tattered 2015 nuclear deal with world powers.

Israel is widely believed to have carried out the sabotage that caused the outage, though it has not claimed it.

Last year, Natanz suffered a mysterious explosion at its advanced centrifuge assembly plant that authorities later described as sabotage. Iran now is rebuilding that facility deep inside a nearby mountain. Iran also blamed Israel for the November killing of a scientist who began the country's military nuclear program decades earlier.

With reporting by AP