By William Maclean
BUNIA, Congo, Feb 27 (Reuters) - Congo's government, trying to assert its authority in the volatile east, hurriedly sent its defence minister on his first visit to remote Ituri on Sunday after militiamen killed nine U.N. peacekeepers.

The visit by the minister, Adolphe Onusumba, was also aimed at countering a local belief that the government in faraway Kinshasa lacks both the means and the will to stop six years of militia conflict in Ituri that has cost 50,000 lives.

Onusumba said the government army would work more closely with the U.N. mission in Democratic Republic of Congo (DRC) to crush ethnic-based gangs involved in an intensifying war that has displaced 70,000 people since the start of the year.

"No on can remain indifferent to what happened - the killing of those who voluntarily came to help us get the country out of its difficulties," he told reporters on arrival in the Ituri capital of Bunia.

He was referring to the slaying by unidentified attackers on Thursday of nine Bangladeshi troops deployed in Ituri in a peacekeeping force known by its French acronym, MONUC, the U.N.'s largest single peace mission anywhere.

It was MONUC's biggest single loss since it deployed in 1999 as part of efforts to end a five-year war in Congo that led, according to one aid agency, to the death of an estimated four million people, mainly through hunger and disease.

"IGNOBLE ACT"

"The first priority is to repair the morale of MONUC troops because what happened was deplorable. Then we must send a strong signal that authority exists in the shape of the government and assume our responsibility in this struggle," Onusumba said.

"We will deploy trained and integrated elements in the places where MONUC is exposed ... Our intention is to send a strong signal to those who have committed this ignoble act. They should henceforth know that such acts will not go unpunished."

He gave no details but vowed to find the killers. "We have put all efforts in place so that the intelligence services can tell us what really happened and to find out who were the brains behind it," he said.

A U.N. military source said MONUC was bringing more troops and aircraft to Ituri in preparation for operations to hunt down the attackers. A MONUC spokesperson said no operations were underway on Sunday.

The gold-mining badlands of Ituri - exploited for years by foreign and Congolese businessmen who employ local militias for security -- are in the grip of worsening political and ethnic instability.

Townsfolk in Bunia are worried that fresh mayhem along the western shores of Lake Albert on the Ugandan border may now undermine the precarious stability of their own community, where thousands were massacred in ethnic bloodletting in 2003.

Fighting between militias from the Hema and Lendu ethnic communities has killed at least 50,000 civilians since 1999, damaging efforts by the former Belgian colony to recover from its wider war.

(Additional reporting by David Lewis in Kinshasa)