The Foreign Ministry on Wednesday said three Israelis are unaccounted for in Haiti, which was struck on Tuesday by the worst earthquake the area has known in the last 200 years.

The Foreign Ministry on Wednesday dispatched a rescue team to the disaster-stricken Caribbean country, where thousands were feared dead on Wednesday.

Prime Minister Benjamin Netanyahu on Wednesday ordered the Defense Ministry, Foreign Ministry and Public Security Ministry to act quickly to render humanitarian assistance to the Caribbean nation.

The airport in Port-au-Prince has been closed since the 7.0 quake hit on Tuesday evening, but the Foreign Ministry decided to send the team with the hope that they would be able to land by the time they arrive.

Israeli ambassador to the Dominican Republic, Amos Radian, is scheduled to join the rescue team whose purpose is to gauge the best way Israel can assist with the crisis and decide on the most immediate needs.

IsraAID also planned to send a 12-man search-and-rescue team, which includes emergency medical staff.

Top Israel Defense Forces officers and delegates from relevant services convened for an emergency session first thing in the morning to discuss sending aide.

They also considered sending a field hospital, including doctors and medical equipment, as well as humanitarian aid such as food supplies and tents for those who have remained homeless.

Israel Radio on Wednesday quoted the country's ambassador to Haiti as saying that to his knowledge, there were no Israelis present at the quake site. Army Radio reported that the daughter of late Israeli peace activist Abie Nathan is missing in Haiti.

The powerful earthquake struck Haiti's capital on Tuesday afternoon with withering force, toppling everything from simple shacks to the ornate National Palace and the headquarters of United Nations peacekeepers. The dead and injured lay in the streets even as strong aftershocks rippled through the impoverished Caribbean country.

Women covered in dust crawled from the rubble wailing as others wandered through the streets holding hands. Thousands gathered in public squares late into the night, singing hymns. Many gravely injured people still sat in the streets early Wednesday, pleading for doctors. With almost no emergency services to speak of, the survivors had few other options.

Thousands of buildings were damaged and destroyed throughout the city, and for hours after the quake the air was filled with a choking dust from the debris of fallen buildings.

The scope of the disaster remained unclear, and even a rough estimate of the number of casualties was impossible. But it was clear from a tour of the capital that tens of thousands of people had lost their homes and that many had perished. Many buildings in Haiti are flimsy and dangerous even under normal conditions.

"The hospitals cannot handle all these victims," said Louis-Gerard Gilles, a doctor and former senator, as he helped survivors. "Haiti needs to pray. We all need to pray together."

An Associated Press videographer saw a wrecked hospital where people screamed for help in Petionville, a hillside Port-au-Prince district that is home to many diplomats and wealthy Haitians as well as many poor people.

At a collapsed four-story apartment building, a girl of about 16 stood atop a car, trying to peer inside as several men pulled at a foot sticking out in an attempt to extricate the body. She said her family was inside.

UN peacekeepers, most of whom are from Brazil, were trying to rescue survivors from their collapsed five-story headquarters, but UN peacekeeping chief Alain Le Roy said late Tuesday that as we speak no one has been rescued.

"We know there will be casualties but we cannot give figures for the time being," he said.

Many UN personnel were missing, he said, including mission chief Hedi Annabi, who was in the building when the quake struck. Some 9,000 peacekeepers have been in Haiti since a 2004 rebellion ousted the president.

Taiwan's Foreign Ministry said its embassy was destroyed and the ambassador hospitalized for undisclosed injuries.

The National Palace crumbled into itself, but Haiti's ambassador to Mexico Robert Manuel said President Rene Preval and his wife survived the earthquake. He had no details.

The 7.0-magnitude quake struck at 4:53 P.M. Tuesday, centered 15kilometers west of Port-au-Prince at a depth of 8 kilometers, the U.S. Geological Survey said. USGS geophysicist Kristin Marano called it the strongest earthquake since 1770 in what is now Haiti. In 1946, a magnitude-8.1 quake struck the Dominican Republic and also shook Haiti, producing a tsunami that killed 1,790 people.

The temblor appeared to have occurred along a strike-slip fault, where one side of a vertical fault slips horizontally past the other, said earthquake expert Tom Jordan at the University of Southern California. The quake's size and proximity to populated Port-au-Prince likely caused widespread casualties and structural damage, he said.

"It's going to be a real killer," he said. "Whenever something like this happens, you just hope for the best."

Most of Haiti's 9 million people are desperately poor, and after years of political instability the country has no real construction standards. In November 2008, following the collapse of a school in Petionville, the mayor of Port-au-Prince estimated about 60 percent of the buildings were shoddily built and unsafe in normal circumstances.

Tuesday's quake was felt in the Dominican Republic, which shares a border with Haiti on the island of Hispaniola, and some panicked residents in the capital of Santo Domingo fled from their shaking homes. But no major damage was reported there. In eastern Cuba, houses shook but there were also no reports of significant damage.