United Nations peacekeepers in Haiti have launched an operation to take control of one of the most violent slums in the capital, Port-au-Prince.
Peacekeepers have been criticised for failing to halt the anarchy
Hundreds of troops moved into the Cite Soleil district by land, sea and air.
The UN says they will stay for at least two months before handing control to local police.
Cite Soleil is a stronghold of the former Haitian President Jean-Bertrand Aristide's supporters, and often witnesses factional violence.
Dozens of people are said to have been killed since fighting increased in early September in the area, home to 500,000 people.
Haiti's interim government has criticised UN forces for failing to do enough to stop the anarchy.
A UN spokesman said peacekeepers would now establish a permanent presence in the troubled quarter.
Brazilian, Chilean and Sri Lankan troops took part in the
operation, backed by the Chilean air force, as well as Chinese and Jordanian riot police, he said.
"This operation will create an environment in which Cite
Soleil can open again to humanitarian action," he said.
Haiti, the poorest country in the Americas, is still in turmoil after Mr Aristide was ousted in February.
It is also recovering from devastating floods in May and September, which killed many hundreds of people.