Rescue teams searched Thursday for survivors of an earthquake that killed at least 12 people, toppled buildings and sowed panic less than three weeks after a massive deadly quake in the same area.

Television footage showed the injured being treated at tents as private CNN-Turk television reported that most of the hospitals damaged during the quake were emptied.

Officials late Thursday raised the death toll to 12 victims, including a Japanese humanitarian worker, Atsushi Miyazaki. At least 28 people were pulled out alive, according to the prime minister's disaster and emergency management centre.

More than 800 rescue personnel rushed to the area, with mechanical diggers clawing through rubble after the 5.6 magnitude quake struck near the city of Van on Wednesday, sending two hotels crashing down along with two dozen mostly empty buildings.

Among those recovered from the rubble were two members of a Japanese humanitarian association who had arrived in the area to help after a 7.2 magnitude quake struck on October 23, killing more than 600 people and injuring more than 4,150.

But one of the Japanese women later died of her injuries, while the other injured Japanese aid worker, Miyuki Konnai, was treated and released from hospital on Thursday, a Japanese diplomatic source said.

It was not clear how many people remained trapped under the rubble.

"When I came out there was nothing but a cloud of smoke everywhere," said Recep Ozhan, a receptionist at one of the two collapsed hotels.

"There were 32 clients registered at the hotel yesterday, but I don't know how many were inside the building... I don't know if anyone was able to get out besides me," he said.

One of the hotels was a six-storey building in Van city centre that housed mostly journalists and teams from the Turkish Red Crescent, NTV television reported.

Aslan Bayram, owner of the collapsed Bayram Hotel -- one of the oldest in the city -- said through the media that his property was examined by experts after last month's quake and authorities gave it the all-clear.

But television stations aired a video showing the inside of the hotel after the earlier quake with deep cracks on the walls.

Turkish authorities, heavily criticised at home for a sluggish response to the October quake, said they rushed nine planes carrying almost 300 rescuers to the region overnight Wednesday along with 50 ambulances and 250 medical personnel.

"What is comforting is that 23 out of 25 buildings (that collapsed) were already empty," Vice Prime Minister Besir Atalay told journalists as he toured the area.

"There were people only in the two hotels and that is where the work is currently going on," Anatolia quoted him as saying.

He declined to give a figure on how many people had been in the two hotels.

"There are contradictory figures," Atalay said. "The hotel owners gave us one set of figures, but security cameras showed that a number of people had left" the buildings.

Atalay added that there were reports of damage in the villages but no residents were missing.

As rescuers picked through the rubble on the ground, 23 planes and eight medical helicopters were ferrying materiel and personnel to and from the area, where snow is forecast for Friday.

Wednesday's quake occurred at 1923 GMT, with the epicentre in the Edremit district, some 15 kilometres (nine miles) from Van province, according to the Istanbul-based Kandilli Observatory. The USGS put the magnitude at 5.6, after having earlier put it at 5.7.

The US Geological Survey said the epicentre was 16 kilometres (10 miles) south of Van, with its depth given as five kilometres (three miles).

Experts told Turkish television stations that a moderate quake of 5.6 magnitude would not normally cause major damage but said that the buildings that collapsed had already been weakened by the stronger October quake.

Following that earlier quake, Turkey accepted help from dozens of countries, including Israel and Armenia with which it has frosty relations.

That quake destroyed many homes in Van province near Iran, including more than 5,000 in the regional capital, provoking claims that building standards had been flouted.

Many survivors were forced to camp out in tents or makeshift shelters, fearing further building collapses with rain and snow adding to their misery.

Turkey is earthquake-prone due to it being crossed by several fault lines.

In 1999, two strong quakes in the heavily populated and industrialised regions of northwest Turkey left some 20,000 people dead.