The Ebola lockdown in the northern Tonkolili district of Sierra Leone was extended on Sunday for two weeks as authorities stepped up the fight to contain the epidemic.
The move comes as the government imposed "additional screening measures" at Freetown International Airport after two workers apparently caught the disease.
A five-day lockdown had been declared by the government across the badly-hit north of the country last month.
More than 70 cases of the virus had been confirmed in Tonkolili during a five-week locked down there ordered by local authorities, District Coordinator Salieu Bah told journalists.
"The lockdown is extended for another two weeks to intensify monitoring efforts by all sectors in the district as we need this mopping up operation until January 17," he added.
He said people had been "reluctant to comply with health rules such as late reporting of suspected Ebola cases and undertaking secret burials."
Meanwhile, Health Minister Dr Abubakarr Fofanah said screening of workers at the airport in Freetown will now be done "on a 24-hour basis to detect any suspicion of Ebola on a worker or traveller".
The National Ebola Response Centre (NERC) said "a case of Ebola was detected and confirmed by laboratory test on Friday involving a person who worked at the airport up to mid-December but had not worked since that time."
Another airport employee who had been in contact with the person has not come to work since Christmas Day. "Due to these developments, additional measures have been put in place to enhance robust screening," NERC said in a statement.
"These include documentation of employees temperatures at the airport front gate and entry to the terminal."
Sierra Leone has overtaken Liberia as the country worst hit by the virus, with 2,758 confirmed deaths out of 9,446 cases, according to the UN.