Masked Palestinians kidnapped a BBC reporter at gunpoint from his car in Gaza City on Monday, Palestinian security officials said.
As he was being taken, the journalist threw a business card on the street that identified him as Alan Johnston of the BBC, the officials said.
The BBC press office in London issued a brief statement saying it was "currently unable to contact him and are concerned for his safety. We are trying to gather as much information as possible."
Four gunmen carried out the kidnapping, and Johnston's car was found abandoned near his Gaza City apartment, said the security officials, who asked that their names not be used as they were not authorized to speak to the media. Police found the lease of the rental car, which stated the vehicle was rented to the BBC.
After the kidnapping, Palestinian security forces set up spotty security checks on roads leading out of Gaza City to the south.
No one claimed responsibility for the abduction.
In Gaza City, a spokesman for Hamas, the Islamic militant group which heads the Palestinian government, condemned the kidnapping.
"We call on these criminal groups to stop this destruction of our reputation and to let this journalist free," spokesman Fawzi Barhoum told The Associated Press.
Interior Minister Said Siyam said in a statement on the Hamas Web site that security branches under his control were investigating the incident. "There are suspicious figures behind this kidnapping," Siyam said, without elaborating.
BBC said Johnston was from Scotland and had been reporting from Gaza for the past three years. The BBC bureau chief in Jerusalem, Simon Wilson, said he could not confirm a kidnapping.
The Tel Aviv-based Foreign Press Association, which represents foreign journalists in Israel and the Palestinian areas, appealed for Johnston's immediate release.
"We ask all in Gaza to respect the rights and safety of the press," the FPA said in a statement.
In the past 18 months, more than a dozen foreign journalists and aid workers have been abducted in Gaza, an area plagued by crime, political violence and lawlessness. Most of the kidnappings have been carried out by gunmen seeking favors from the government or trying to settle scores with rivals.
In most cases, victims have been released unharmed within hours. An exception was the abduction of two Fox News employees last summer who were held for two weeks, prompting many foreign journalists to shy from entering Gaza.
The last foreigner taken hostage was Jaime Razuri, 50, a Peruvian photographer with the French news agency, who was abducted at gunpoint on Jan. 1 and released a week later.
In October, AP photographer Emilio Morenatti was abducted in Gaza City and freed unharmed after 15 hours.