Security forces in Liberia's capital Monrovia have deployed to enforce a quarantine in a large slum area in order to contain the spread of Ebola.

The move set off protests from angry residents in West Point and people gathered at roadblocks to complain.

The president has also ordered a countrywide night-time curfew as part of new anti-Ebola measures.

Since the beginning of the year, 1350 people have died of the virus in four West African countries.

New UN figures show that between 17 and 18 August, there were 221 new cases and 106 deaths.

A top Lagos doctor has just died of the virus, bringing the number of people who have died of Ebola in Nigeria to five, the health ministry said.

Colleagues said consultant Stella Ameyo Adadevo was the first medic to order that a sick patient from Liberia be tested for Ebola when he was admitted in July.

"We owe her a lot; she managed the situation like a thorough professional that she was. She had helped Nigeria to contain the epidemic in her own way," Akin Osibogun, the chief medical director at Lagos University Teaching Hospital, told Nigeria's Premium Times newspaper.

Kenyan travel restrictions have now taken effect, blocking travellers from Liberia, Sierra Leone and Guinea - the three countries most affected by the outbreak. Earlier this week Cameroon shut its border with Nigeria.

'Teargas fired'

There is no known cure for Ebola, but the WHO has ruled that untested drugs can be used to treat patients in light of the scale of the current outbreak - the deadliest to date.

The experimental drug ZMapp has been used to treat several people who contracted Ebola in Liberia but the US firm that makes the drug says it has for now run out of it, so the only way to stop the current outbreak is to isolate the victims.

The BBC's Jonathan Paye-Layleh in Monrovia says troops are patrolling in West Point, the country's largest slum which is home to more than 50,000 and sprawls along the Atlantic coast. Ferries have been halted and coast-guard boats are monitoring the coastline.