Among the first to arrive was a team from Turkey, reciprocating the Greek help in last month's disastrous quake.

The Turkish team began rescue work at the Ricomex detergent factory, where about a dozen workers were believed to be still trapped.

The BBC's Jonathan Charles: "Many people are afraid to return home"

Teams from Switzerland and France have also arrived in Athens, and more rescuers are expected from Ukraine with sniffer dogs later on Wednesday.

Rescuers worked through the night to try to save people trapped under buildings which collapsed at a shock measuring 5.9 on the Richter scale struck the northern suburbs of the city.

A sniffer dog at work in the debris of a building in the Athens suburb of Nea Philadelphia

More than 700 aftershocks shook Athens overnight, some as high as 4.7 on the Richter scale.

Thousands of Athenians slept in cars or makeshift camps in parks and squares for fear of further collapses.

Huge cranes lifted slabs of concrete and workers dug tunnels through the debris, following the sounds of people trapped underneath. About 45 were pulled out by early Wednesday.

More were thought to be under the rubble of a household appliance showroom and a five-storey block of flats.

Among the known fatalities were 12 children. Another 61 people are still missing. The Health Ministry reported that 250 people had been injured.

Turkish solidarity

This four-storey building was ripped apart by the earthquake

Turkish President Suleyman Demirel said: "We profoundly feel and share the pain you have from the loss of life and property in today's earthquake because of the earthquake disaster we recently experienced."

The Prime Minister, Costas Simitis, visited one of the factory where rescue attempts were in progress. He ordered that tents which had been bound for Turkey be distributed at first light among the Greeks who need them.

Shut down

The BBC's Colin Blane reports from Athens

Many office workers did not show up for work on Wednesday, many shops remained closed and all schools in Athens were closed as people dealt with family emergencies.

Rescuers have divided the disaster zone into 31 sites.

Meanwhile the Greek government has begun assessing the damage, sending engineers to mark buildings.

"About 500 ministry engineers have started to evaluate the condition of buildings," Environment Minister Costas Laliotis told reporters. "The state machine is at full readiness."

Buldings will be marked with red, yellow or green paint to indicate if they can be used. The ministry was setting up organised camps for the homeless, Mr Laliotis said.

Officials said more than 100 buildings were severely damaged.

The government said homeless families would be put up in hotels and given 200,000 drachmas ($650) each in emergency aid.

But amid widespread damage, the historic buildings on and around the Acropolis escaped unscathed.