By Katya Adler
BBC News, Jerusalem
Renewed attempts are being made to find BBC Gaza correspondent Alan Johnston, who has been missing since Monday afternoon and is feared kidnapped.
Johnston has been the BBC's reporter in Gaza for three years
The BBC has sent a team to Gaza to liaise with Palestinian officials.
Palestinian security officials say he was kidnapped from his car by masked gunmen, but the BBC says it cannot independently verify these reports.
Other reports in Gaza say he is healthy and negotiations are under way with the abductors to secure his release.
ALAN GRAHAM JOHNSTON
Born in Lindi, Tanzania, on 17 May 1962
Graduated with an MA in English and Politics from Dundee University, Scotland, and a diploma in Journalism Studies from the University of Wales in Cardiff
Joined the BBC World Service in 1991. He has been a correspondent in Uzbekistan, Afghanistan and Gaza
The BBC says it is continuing to work with the Palestinian authorities and others to establish the facts surrounding Alan Johnston's disappearance.
He disappeared on Monday after leaving the BBC office in Gaza City.
There has been a series of abductions of Westerners in the increasingly lawless Gaza Strip.
All were eventually released unharmed.
The motives for the abductions were mainly local: unpaid salaries, demands for jobs or the release of jailed family members.