Anger built on Saturday at Haiti's US-controlled main airport, where aid flights were still being turned away and poor coordination continued to hamper the relief effort four days on. "Let's take over the runway," shouted one voice. "We need to send a message to (US President Barack) Obama," cried another. Control remained in the hands of US forces, who face criticism for the continued disarray at the overwhelmed airfield. Dozens of French citizens and dual Haitian-French nationals crowded the airport on Saturday seeking to be evacuated after Tuesday's massive 7.0 earthquake, which levelled much of the capital Port-au-Prince. But at the last minute, a plane due to take them to the French island of Guadeloupe was prevented from landing, leaving them to sleep on the tarmac, waiting for a way out. "They're repatriating the Americans and not anyone else," said Charles Misteder (50). "The American monopoly has to end. They are dominating us and not allowing us to return home." The crowd accused American forces, who were handed control of the airport by Haitian authorities, of monopolising the airfield's single runway to evacuate their own citizens. The US embassy denied it was putting the evacuation of the approximately 40 000 to 45 000 American citizens in the country first. Others waiting for a way out were taken aback by the chaotic scenes confronted them when they arrived at the Toussaint L'Ouverture airport. "I haven't been able to tell my family that I'm alive. The coordination is a joke," said Wilfried Brevil, a 33-year-old housekeeper. The US ambassador to Haiti defended American efforts at the small airport, which was up-and-running 24 hours after the massive quake, even though the air traffic control tower was damaged. "We're working in coordination with the United Nations and the Haitians," said Ambassador Kenneth Merten, though he acknowledged some difficulties. "Clearly it's necessary to prioritise the planes. It's clear that there's a problem."