LES CAYES, Haiti -- The death toll in Haiti's powerful earthquake jumped to over 1,200 on Sunday, as crews desperately dug through collapsed buildings for survivors in the Caribbean nation still reeling from its president's assassination.

In Les Cayes, as in other hard-hit cities on the southwestern peninsula, most of the population spent the night sleeping outdoors in front of their houses -- or what remained of them -- amid fears of new aftershocks.

The streets there were filled with the grinding sounds of heavy equipment lifting debris from collapsed buildings, as well as the quieter sounds of people pulling away rubble by hand in desperate searches for the missing.

"Thanks to God and also to my phone, I'm alive," said Marcel Francois, who was rescued from his collapsed two-story home in hard-hit Les Cayes.

His younger brother Job Francois said a desperate-sounding Marcel had called to say, "'Come save me, I'm under the concrete'... He told me he couldn't breathe, that he was dying."

The neighbors and Job spent hours freeing him and his 10-year-old daughter from the heavy debris.

But at least 1,297 people were killed in the 7.2-magnitude tremor that struck Saturday about 100 miles (160 kilometers) to the west of the densely populated capital Port-au-Prince, which was devastated in a massive 2010 quake.

Some 13,600 buildings were destroyed and over 13,700 damaged, trapping hundreds under rubble and leaving more than 5,700 people injured, the country's civil protection agency said in an update.

- President assassinated -
Rescuers face new pressure as Tropical Depression Grace approaches, raising fears of torrential rainfall, flash floods and mudslides from late Monday, according to the US National Weather Service.

The United States and other nations have pledged to help Haiti cope with this latest disaster.

USAID head Samantha Power tweeted Sunday that her agency had deployed a 65-person urban search and rescue team -- equipped with "specialized tools, equipment & medical supplies" -- to join an earthquake disaster response team already in Haiti.

Haiti's neighbor the Dominican Republic said it was shipping 10,000 food rations and medical equipment. Mexico also sent an aid shipment. Cuba and Ecuador dispatched medical or search-and-rescue teams.

And Chile, Argentina, Peru and Venezuela also offered help, as did the United Nations.

"We want to plan a better adapted response than in 2010 after the earthquake -- all aid coming from abroad should be coordinated by the Civil Protection agency," said Haiti's Prime Minister Ariel Henry.

A 7.0-magnitude quake in January 2010 left much of Port-au-Prince and nearby cities in ruins, killing more than 200,000.

More than 1.5 million Haitians were made homeless in that disaster, which also destroyed 60 percent of Haiti's healthcare system, leaving island authorities and the international humanitarian community with a colossal challenge.

The latest quake comes just over a month after President Jovenel Moise was assassinated in his home by a team of gunmen, shaking a country already battling poverty, spiraling gang violence and Covid-19.

Police say they have arrested 44 people in connection with the killing.