* Authorities say lockdown required to fight complacency
* Some residents defy lockdown in search of food, water
* Sierra Leone has reported nearly 12,000 Ebola cases (Adds quote from resident of Devil Hole, further detail)
By Josephus Olu-Mammah and Umaru Fofana
FREETOWN, March 28 (Reuters) - Police fired tear gas at an angry crowd fighting over food supplies in Sierra Leone on Saturday, while other residents defied a three-day national lockdown that the government hopes will accelerate the end of the Ebola epidemic.
Sierra Leone has reported nearly 12,000 cases and more than 3,000 deaths since the worst Ebola epidemic in history was detected in neighboring Guinea a year ago.
New cases have fallen sharply since a peak of more than 500 a week in December but the government says the lockdown, its second, is necessary to identify the last cases and to buck a worrying trend towards complacency.
Officials have ordered the six million residents to stay indoors on pain of arrest as hundreds of health officials go door-to-door looking for hidden patients and educating residents about the haemorrhagic fever.
Residents in and around Freetown, one of the last Ebola hotspots, were told to stock up on food and water but on the second day of the campaign some said they had already run out. Officials are distributing supplies only in very poor areas.
In the Devil Hole neighborhood hundreds of people left their homes to gather at a food collection point. Some residents complained they had not received food and fighting broke out until police arrived to scatter the crowd, making several arrests.
"People are desperate for food because of how the distribution is going," said resident Adam Dumbuya. "This has led to panic."
SOLDIERS MAINTAIN ORDER
Elsewhere in the dense slums of eastern and central Freetown, residents defied the lockdown rules and wandered out onto the streets in search of supplies.
"We have exhausted this morning all we could manage to stock up," said 51-year-old Ibrahim Kanu, a father of six, as he struggled to get rice in the crowd at East Brook Street in Freetown. Soldiers put a cordon in place there to contain the swelling crowd where people stood packed together, despite the risks of Ebola transmission via bodily fluids such as blood and sweat.
At Kissy Road in the east of Freetown, mostly women and children wandered into the twisting streets with buckets and yellow jerry cans to replenish water supplies. One man wandered out to bathe in a sewer, a Reuters reporter said.
Some charities have criticized lockdowns as heavy-handed and counter-productive, pointing to riots in neighboring Liberia's capital last August in which a teenaged boy was killed.
Sierra Leone's authorities have made exemptions for locals to attend church services on Palm Sunday.
Other officials said the campaign was making progress.
"Households visited have been responsive to the messages and the distribution of soap has been well received," said Red Cross emergency health coordinator John Fleming. (Reporting by Josephus Olu-Mammah and Umaru Fofana; Writing by Emma Farge; Editing by Stephen Powell and Greg Mahlich)