ANKARA, Turkey (AP) — Turkish authorities on Friday said preliminary work has started to build housing for people left homeless by the massive earthquake that hit parts of the country and neighboring Syria, killing tens of thousands.

Murat Kurum, the minister for the environment, urbanization and climate change, said on Twitter that excavations were taking place in the towns of Nurdagi and Islahiye in Gaziantep province, where the government plans to build an initial 855 homes.

The work comes less than three weeks after the magnitude 7.8 quake struck, killing more than 47,000 people in Turkey and Syria — the vast majority in Turkey. Turkish authorities say some 173,000 buildings, containing around 534,000 apartments or other units, either collapsed or were severely damaged in the Feb. 6 quake and other strong tremors likely linked to it.

Turkish President Recep Tayyip Erdogan, who faces tough elections in either May or June, has promised to reconstruct homes within the year, although critics have warned that moving too fast could just lead to the erection of more sub-standard homes.

Opposition parties have also held Erdogan’s government — in power for the past two decades — responsible for the extent of the disaster, accusing it of failing to enforce building regulations.

Experts say many of the toppled structures were built with inferior materials and methods, and often did not comply with government standards.

On Friday, the United Nations Children’s Fund said more than a million people were staying in temporary accommodation, including gyms, stadiums, hotel and dormitories, with limited access to essential services.

“The children and families who survived the earthquake now face homelessness, lack of food and water, and temperatures that regularly drop below freezing at night,” said Afshan Khan, UNICEF’s regional director for Europe and Central Asia.

Kurum, the urbanization minister, posted a video of excavators clearing terrain.

“All our effort is (geared toward) bringing homes to our citizens as soon as possible,” he wrote. “We immediately got to work in areas where we have signed contracts and completed ground survey work.”

Earlier on Friday, Erdogan issued a decree which among other things enables individuals, companies or organizations to build homes or offices and donate them to Kurum’s ministry which would then give them to people who lost homes or businesses.

Justice Minister Bekir Bozdag said late Thursday that 583 contractors or other people suspected of responsibility over buildings that have collapsed were being investigated and 171 have been arrested.