Turkish authorities are racing to provide shelter for thousands of earthquake victims left homeless and battling rain and snow.

Officials say the death toll from Sunday's 7.2 magnitude tremor has risen to 523 with at least 1,600 people injured.

Authorities expect the death toll to continue to climb as more bodies are pulled from the rubble. Three people were found alive Wednesday in Ercis.

Some international aid, including tents, clothing, and food, has already arrived in Turkey.

Ankara initially only accepted help from Iran and Azerbaijan, which border the heavily damaged area. Turkish officials later accepted aid from other countries, including Israel, with which it has strained relations.

Many displaced residents complain the government is not acting fast enough to distribute aid.

Turkey's Red Crescent organization said 17 trucks were looted Wednesday.

The International Federation of the Red Cross says its Turkish chapter is working to assist survivors. The Red Cross says more than 7,500 tents and 22,000 blankets have been distributed, as well as stoves, food and clean water.

World leaders have sent condolences to Turkey. Russian President Dmitry Medvedev and President Serzh Sarkisian of Armenia made a joint telephone call to Turkish President Abdullah Gul to express their sympathies. U.S. President Barack Obama said the United States will stand “shoulder to shoulder” with Turkey during this difficult time.

United Nations Secretary-General Ban Ki-moon praised Turkish authorities for their rapid response to the disaster and said the U.N. remains ready to offer help if requested.