Haitian President Rene Preval has said estimates of the death toll in the devastating earthquake in capital Port-au-Prince could easily be in the tens of thousands, while other officials said more than 100,000 may have perished.

"Up to now I've heard 50,000, I've heard 30,000. Let's say, it's too early to give a number," Preval told broadcaster CNN, conceding that any sort of official estimate was extremely difficult. "I am still trying to understand myself the magnitude of the event."