BRASILIA - The delay in getting water, food and shelter to the desperate population of Haiti's capital is raising "the risk of riots," Brazilian Defense Minister Nelson Jobim warned Friday after visiting the quake-hit city.

"We are worried about security," he bluntly told reporters on arrival in Brasilia after a two-day stay in Port-au-Prince.

"As long as the people are hungry and thirsty, as long as we haven't fixed the problem of shelter, we run the risk of riots," he said.

Brazil is in command of the 9,000 UN peacekeeping force deployed to Haiti before the quake, and is using its 1,260 troops for disaster relief efforts.

It lost 17 of its citizens in the quake, according to Jobim.

They were: 14 soldiers in the peacekeeping mission; a high-profile civilian campaigner for children's rights, Zilda Arns; the deputy UN representative in Haiti, Luiz Carlos da Costa; and another, unidentified Brazilian.

Another four Brazilian soldiers were missing, though Jobim said that term was really a "euphemism," suggesting he believed they were also dead.

The Brazilian army said 25 of its soldiers were injured in the quake. The Globo news website said 16 of them arrived in Brazil on Friday for medical treatment.

One of them, Corporal Carlos Pimentel de Almeida, told a televised media conference that, when the quake struck, he thought his military post was under attack.

"I thought it was an attack... that a bomb exploded," he said.

He showed a head wound he sustained from falling debris and recounted that several of his comrades died when the building collapsed.

He added that, once recovered, he wanted to return to Haiti "because the population needs help."

Brazil has sent at least six flights full of aid for Haiti's quake survivors and its troops, including water, food, medical supplies and rescue personnel. More were due to leave Friday.