Dozens of Egyptian truck drivers are being held in the Libyan city of Ajdabiya by armed men demanding the release of Libyan prisoners detained in Egypt, Libyan security officials said.
Egypt's Foreign Ministry has asked Libya to secure the release of the drivers and their trucks, Badr Abdel-Atti, a ministry spokesman, said on Saturday.
It was not clear exactly how many Egyptians were captured.
Libyan security officials, however, said about 200 Egyptian drivers were detained by the armed group, which demands the release of their relatives arrested in Egypt on accusations of arms smuggling.
Al Jazeera's sources in Ajdabiya said on Sunday that the families of the Libyan prisoners will hold the drivers until their demands are met.
Ajdabiya is an area largely controlled by units of the Petroleum Facilities Guard, which have been blockading eastern oil terminals in a wide-ranging dispute with Prime Minister Ali Zeidan's government, according to the Libya Herald newspaper.
The newspaper reported that Egyptian authorities set up a crisis centre at their Benghazi consulate, and were given a list of 13 names of the Libyan prisoners.
The Libyans detained in Egypt are reportedly fishermen who were arrested after accidentally crossing the Libyan-Egyptian border and clashing with Egyptian troops stationed in these areas several months ago.
Leaked reports said that harsh verdicts were issued against them, ranging from 15 years in prison to death sentences.
El-Anani Hamoud, head of Marsa Matrouh's security police, said that authorities had decided to close the Salloum crossing with Libya until further notice.
Armed groups have increased in number and force after Muammar Gaddafi was overthrown and killed in 2011. In the aftermath, Libyan weapons have flooded Egypt while authorities struggle to contain a low level fighting.