A moderate earthquake shook Tehran, a city on edge after months of war, with residents in different parts of the city saying they felt the ground jolt and roll around midnight.

Tehran, the sprawling capital of Iran with 15 million residents, sits on or near several major fault lines and occasionally is hit with earthquakes. “We shook as if we were in a swing,” said Saboor a resident of Tehran in a text message.

The U.S. Geological Survey registered it as magnitude 4.3, the Euro-Mediterranean Seismological Centre at 4.5 and Iranian state media at 4.6. Earthquakes in that range can damage buildings that are not up to advanced structural standards. Seismologists often revise an earthquake’s reported magnitude after reviewing available data.

There were no immediate reports of damage or casualties.

Iranian media reported that the earthquake’s epicenter was at the border of Tehran and Mazandaran provinces, east of the capital, and said the ground shook for 10 seconds. Earlier on Tuesday, there was a report of a small earthquake in the Pardis area near Tehran.

The U.S.G.S. said the tremor was centered near the city of Damavand.

Residents said their nerves were already frayed as they are hanging in limbo of neither peace nor all-out war, wondering if a tenuous cease-fire will collapse and the United States and Israel will strike again.

Sara, a 54-year-old resident of Tehran, said her apartment tower in northern Tehran swayed, and she panicked.

“I was sitting at the kitchen table and suddenly felt as if the chair was being pulled from under me,” she said in a voice message from Tehran. “I thought, ‘I’m having a dizzy spell’ then noticed the chandeliers swinging. I thought it was an attack — earthquake was the last thing on our minds.”