JAKARTA, March 1 (AFP) - Scenes of Indonesian soldiers and police standing by as frenzied Dayak mobs terrorise migrant Muslim settlers on Borneo and loot and torch their homes are horrifying, but normal, say seasoned observers here.

Some say the security forces' failure to prevent the savage ethnic cleansing -- which has claimed more than 400 settlers' lives and forced tens of thousands to flee -- is deliberate, aimed at undermining the government and proving that the once-mighty military is needed to run the country.

Others say it is plain incompetence and unprofessionalism.

Residents of Central Kalimantan province, where indigenous Dayaks have rampaged for 10 days butchering and beheading settlers from Madura island, say sheer terror is behind the troops' apparent impotence.

"The military here knows if they try to stop the Dayaks, they could be killed, because there is a mob out there," one Dayak boasted to AFP in Palagkaraya, as dozens of trucks crammed with Dayaks whooping and brandishing spears careened past unflinching police.

Zainuddin, a Javanese migrant who came to Borneo in 1962, said the troops were outnumbered and frightened.

"It is very difficult for the police or military to disperse the mobs and quell the looting because they lack manpower," he told AFP.

"It is also because they fear for their own safety."

Zainuddin dismissed theories of complicity by the troops.

"As far as I know the security forces here have not made any deals with the Dayak leaders to allow them to destroy homes," he said.

"What they are facing is a mob of angry people."

Ayan, 43, a Dayak high school teacher, speculated that the police and soldiers were also afraid of "being accused of violating human rights" -- their albatross since the fall in 1998 of former president Suharto, the ex-general under whom military impunity flourished for 32 years.

Indonesia's state-funded Human Rights Commission accused the troops of downright unprofessionalism.

"They say they lack personnel and equipment. In my opinion they simply have no professionalism," secretary-general Asmara Nababan told AFP.

"It's just like in the Maluku islands, where they've been so unprofessional that the conflict has spread."

Human rights lawyer Johnson Panjaitan, who has documented countless cases of alleged abuses by Indonesia's security forces, charged that the failure to stem the violence was deliberate.

"By letting this descend to the level of blatant ethnic cleansing, they become extremely needed," he told AFP.

"They need to prove that they are needed. Their aim is to stay in power.

The troops' inaction may have soiled further their own credibility, but more important, said Panjaitan, they were dragging down the government's credibility.

"They are showing that the civilian government is no good at governing."

But Nababan said such conclusions were premature.

"It's difficult to draw the conclusion they allowed the conflict to spread to give them a reason to return to the center of power," Nababan said.

"We need more time and evidence to determine that."

Panjaitan linked calls for a civil emergency to what he sees as the military's lust for power.

"This suits the old forces among the top brass, who still want to stay in power."

The chaos also gave troops an opportunity to collect money, Panjaitan charged.

"They're interested in concrete cash. Look at the way they take advantage of the refugees, offering security and escape in exchange for money, as they do in every riot. It's normal."

Army chief, General Endriartono Sutarto said Tuesday that the military was "discussing" with police the need for it to move more swiftly, Detik.com news reported.

Giving the armed forces' the option to take the initiative to handle urgent matters was also under discussion.

"During the transition period such as now, where the police personnel are insufficient in terms of both quantity and quality, all concerned should be able to think clearly and give TNI the opportunity to act," the general said.