A 5.1 magnitude earthquake has struck northern Iran amid a series of Israeli airstrikes, the United States Geological Survey (USGS) said.

The USGS said the quake struck at a depth of 10 kilometers (6 miles) and about 37 kilometers (23 miles) southwest of the Iranian city of Semnan. Iran's Tasnim news agency put the magnitude at 5.2.

The Iranian Geological Survey said the earthquake struck near the Fordo nuclear facility in Qom province.

The quake's impact reached as far as the capital Tehran. The epicenter of the quake was the city of Semnan, about 145 miles east of Tehran. The intensity of the tremors was mild and no damage was reported so far.

Meanwhile, rumors surrounding the earthquake have been circulating on social media. An Iranian blogger's Telegram channel suggested that the Islamic Revolutionary Guard Corps (IRGC) may have been conducting some kind of "test." However, the claim has not yet been confirmed, according to the US media outlet Mirror US.

Iran's main media outlets reported the earthquake but did not say anything about the "test." Different media outlets reported the quake as a magnitude 5.2, while others reported a magnitude 5.5.

Local media confirmed that tremors were felt in Tehran. Such tremors are not new to Iran, which is located in an earthquake-prone region.

At the same time, local and regional media outlets reported an Israeli missile attack in southwestern Iran. Israeli media outlet Ynetnews.com said the attack targeted an Iranian air defense installation called "Magar" in the southwestern Behmai province.