Reuters reports Monday's quake, this time with a magnitude of 6.4, was centred near the southern Turkish city of Antakya and was felt in Syria, Egypt and Lebanon.
It struck at a depth of 10 km, the European Mediterranean Seismological Centre (EMSC) said.
Hatay Mayor Lutfu Savas told HaberTurk broadcaster that he had received reports about some people stuck under rubble after the latest quake. Three people were killed and more than 200 injured, Interior Minister Suleyman Soylu said.
In Samandag, where the country's Disaster and Emergency Management Authority AFAD reported one person dead, residents said more buildings collapsed but most of the town had already fled after the initial earthquakes. Mounds of debris and discarded furniture lined the dark, abandoned streets.
Muna Al Omar said she was in a tent in a park in central Antakya when the ground started heaving again.
"I thought the earth was going to split open under my feet," she said, crying as she held her 7-year-old son in her arms.
Hours earlier, US Secretary of State Antony Blinken said on a visit to Turkey that Washington would help "for as long as it takes" as rescue operations in the wake of the Feb. 6 earthquake and its aftershocks were winding down, and focus turned to toward urgent shelter and reconstruction work.
The death toll from the quakes two weeks ago rose to 41,156 in Turkey, AFAD said on Monday, and it was expected to climb further, with 385,000 apartments known to have been destroyed or seriously damaged and many people still missing.
President Tayyip Erdogan said construction work on nearly 200,000 apartments in 11 earthquake-hit provinces of Turkey would begin next month.
Total US humanitarian assistance to support the earthquake response in Turkey and Syria has reached $185 million, the US State Department said.
Among the survivors of the earthquakes are about 356,000 pregnant women who urgently need access to health services, the UN sexual and reproductive health agency has said.
They include 226,000 women in Turkey and 130,000 in Syria, about 38,800 of whom will deliver in the next month. Many of them were sheltering in camps or exposed to freezing temperatures and struggling to get food or clean water.
A man stands in front buildings in Antakya, southern Turkey on 20 February 2023. The buildings were destroyed in the deadly 7.8 and 7.5-magnitude quakes on 6 February. Photo: AFP