After years being derided as "tourists in a war zone", the United Nations peacekeeping mission in the Democratic Republic of Congo has sent out a new message - that it will get tough on ethnic militias.
The death of UN troops has led to increased efforts to disarm militia
Known as Monuc, the UN force in DR Congo is one of the world's largest, and one of its most controversial.
Nine of its troops were killed last week in an ambush in DR Congo's north-eastern Ituri region, the deadliest attack since Monuc was set up in 1999.
Monuc has responded with a high-profile offensive killing 50 militia fighters.
UN military spokesman Jean-Francois Collot d'Escury told a press conference that the message of the Ituri campaign was: "We know how to fight".
Some 15,000 militia in the region - where a recent surge in violence has forced thousands of civilians to flee - have been warned they face more such operations if they continue to resist pressure to disarm.
Gen Collot d'Escury said Monuc was determined to dismantle camps used by the fighters, even if it meant using force.
The new tough talking follows a year in which Monuc's failure to prevent rebel forces taking control of the key eastern town of Bukavu prompted criticism and anti-UN riots.
The mission's reputation has also been damaged by claims of sexual abuse of women and girls by peacekeeping troops stationed in DR Congo.
Correspondents say the latest offensive marks a significant shift in the way the UN tackles the huge task of maintaining peace in a country the size of Western Europe - and may go some way to restoring its credibility.
The Bukavu debacle last summer pushed the UN Security Council to strengthen the mission's mandate in DR Congo.
A UN Security Council resolution in October 2004 authorised an extra 5,900 personnel for Monuc, taking the official ceiling for troops and police to 16,700.
The mandate for the mission, which includes representatives of more than 40 countries, was also reinforced to "ensure the protection of civilians 'under imminent threat of violence'".
UN spokesman Kemal Saiki told the BBC News website the offensive showed that extra troops in Ituri were starting to make an impact, even though the full deployment has not yet been reached.
"Before, we had a situation where we did not have a critical mass of military means and tools to conduct this kind of operation," he said.
"Our plan is to step up our activities in those parts of the country where there is still a lot of violence and unrest caused by the presence of so-called militias.
Monuc has said it is willing to use violence to dismantle militia camps
"They are basically armed crooks, rather criminal than political, preying on the population and trying to exploit the wealth of the area."
He said the Monuc unit involved in the latest offensive, comprising Pakistani, South African and Nepalese troops, had called in combat helicopters in self-defence after coming under fire while searching for weapons dumps.
And he warned the militia could expect many more such operations if they continued to resist the peacekeepers' efforts to disarm them.
The BBC's Arnaud Zajtman in Kinshasa says most people in DR Congo welcome Monuc's offensive against the Ituri militia as long overdue.
"The real scandal for Monuc for the people was the fact that the UN wasn't imposing the peace that it was supposed to impose, so it wasn't really fulfilling its task," he says.
"Now it's managing to do so, people are happy because that is what they want."
But although Monuc's stance has been welcomed by Congolese ministers, the struggle to quell the country's violence is far from over.
Despite a rise in the number of peacekeepers deployed, Monuc still has far fewer than the 23,900 troops and 500 police recommended by UN Secretary General Kofi Annan last year.
The BBC's Mark Doyle, who was in Ituri late last year, says the Congolese people will remain wary about their security.
They know that the UN force is overstretched, he says, and are also well aware that the international community will only be with them for a limited time.
In the end, he concludes, Congolese politicians will have to sort out a country which has never known democracy and is still reeling from decades of dictatorship and war.