Liberia battled on Tuesday to halt the spread of the Ebola disease in its crowded, run-down oceanside capital Monrovia, recording the most new deaths as fatalities from the world's worst outbreak of the deadly virus rose above 1,200.

The epidemic of the hemorrhagic disease, which can kill up to 90 percent of those it infects, is ravaging the three small West African states of Liberia, Sierra Leone and Guinea, and also has a toehold in Nigeria, Africa's biggest economy.

As the Geneva-based World Health Organization rushed to ramp up the global response to the outbreak first detected in March, including emergency food deliveries to quarantined zones, it announced that deaths from it had risen to 1,299 as of Aug. 16, out of 2,240 cases.

Between Aug. 14-16, Liberia recorded the most new deaths, 53, followed by Sierra Leone with 17, and Guinea with 14.

The WHO said it was working with the U.N.'s World Food Programme (WFP) to ensure food delivery to 1 million people living in Ebola quarantine zones cordoned off by local security forces in a border zone of Guinea, Liberia and Sierra Leone.

"Food has been delivered to hospitalised patients and people under quarantine who are not able to leave their homes to purchase food. Providing regular food supplies is a potent means of limiting unnecessary movement," it said in a statement.

Besides infection in border zones, Liberia is fighting to stop the spread of the virus in the poorest neighbourhoods of its capital, such as the West Point slum where at the weekend a rock-throwing crowd attacked and looted a temporary holding centre for suspected Ebola cases, 17 of whom fled.

As fears of wider contagion increased - Ebola is spread by contact with the bodily fluids of infected persons - Liberia sent police to track down the fugitive suspected cases.

"We are glad to confirm that all of the 17 individuals have been accounted for and have now been transferred to JFK Ebola specialist treatment centre," Liberia's Information Minister Lewis Brown told Reuters on Tuesday.

He added that after meetings with religious and community leaders, a task force was being set up that would go door-to-door through the West Point neighbourhood, a labyrinth of muddy alleys, to explain the risks of the disease and why anyone showing symptoms must be quickly isolated for treatment.

"I know that Monrovia is really of concern to WHO," WHO spokeswoman Fadela Chaib said in Geneva, underlining the importance of containment and isolation measures. "If you contain it, you've won the battle," she said.

Lewis said the Liberian authorities were considering imposing even tougher restrictions on movements. "We realise that we can't police our way out of this. We would prefer community awareness, but we need security back-up," he said.

While Nigeria, Africa's most populous nation and No. 1 oil producer, appears to be containing its smaller outbreak, Liberia and Sierra Leone have been struggling, their weak health systems overwhelmed by the multiplying numbers of cases and deaths.

On Friday, these small two West African nations and a medical charity chided the WHO for its slow response, saying more action was needed to save victims threatened by the disease and hunger.

"IMPROVEMENT" AFTER RARE DRUG USED

The WHO this month gave the green light to use untested pharmaceuticals to treat Ebola patients.

In Monrovia, three African healthcare workers were given the rare experimental ZMapp drug, which has already been used on two American aid workers being treated in the United States after being evacuated from Liberia with Ebola.

Lewis said the three Africans treated with ZMapp were showing "remarkable signs of improvement", quoting an assessment by the doctor overseeing their treatment.

However, the manufacturer of the drug, California-based Mapp Biopharmaceutical, has already said its scarce supplies have been exhausted. Officials have cautioned the public not to place too much hope in untested and scarce treatments.

As part of the increased international response, WFP is stepping up emergency food flights to the quarantined areas, which include severely-affected cities such as Gueckedou in Guinea, Kenema and Kailahun in Sierra Leone and Foya in Liberia.

Fears of the disease and quarantine measures like military and police roadblocks have stopped farmers from reaching their fields, and as a result food output has dropped, raising fears that a famine could set in on top of the deadly illness.

"We think that even beyond the control of the outbreak there will be severe food shortage since farmers are unable to continue with cultivation," said Gon Myers, WFP country director for Sierra Leone. The extra food deliveries would be trying to reach 400,000 people in Sierra Leone alone.

The WHO has told countries affected by the outbreak to screen people departing at airports, seaports and major land border points and stop any with signs of the virus.

It has argued against further travel restrictions, but several international and regional airlines have cancelled services to Liberia, Sierra Leone and Guinea.

Nigeria said on Monday its number of confirmed Ebola cases had reached 12, up from 10 last week, but five of these had almost fully recovered. Four people have died from the virus in Nigeria, where it was transferred by a U.S. citizen who arrived by plane from Liberia. – Reuters