(CNN) -- Two Reuters television journalists have been missing in Syria since Saturday night, when they were supposed to return to Lebanon, the news agency said Sunday.
Producer Ayat Basma, based in Beirut, Lebanon, and cameraman Ezzat Baltaji were expected to cross into Lebanon by road at about 6:30 p.m. GMT (2:30 p.m. ET) Saturday, and had arranged for a taxi to pick them up, according to Reuters. They were last heard from at 5:22 p.m. GMT, when Baltaji sent a message to a colleague in Beirut saying, "We will leave now."
Basma and Baltaji, both Lebanese nationals, "have been unreachable by telephone since Saturday night," Reuters reported Sunday.
The two had traveled to Syria on Thursday to cover the unrest in the country. Protests have been ongoing in recent weeks, in which opponents of President Bashar al-Assad allege human rights abuses. Protesters have also been calling for the lifting of an emergency law that has been in effect since 1963. A government spokeswoman said Sunday the emergency law would be lifted, but did not say when.
"Reuters is deeply concerned about our two Reuters television colleagues who went missing in Syria on Saturday," Reuters Editor-In-Chief Stephen Adler said. "We have reached out to the relevant authorities in Syria and have asked for their help in securing our colleagues' safe return home."
A senior Reuters editor was planning to travel to Damascus to discuss the matter formally with Syrian officials, the news agency reported Sunday.
Basma has been with Reuters since February 2007, and Baltaji since April 2008.
On Friday, Reuters said, Syrian authorities withdrew the accreditation from Reuters text correspondent Khaled Yacoub Oweis, saying his coverage of recent events in Syria was "unprofessional and false." The news agency said it stands by its coverage.
CNN has been unable to independently confirm accounts of the unrest in Syria, as it has not been granted access to the country by the Syrian government.
In a July posting on its website, Reporters Without Borders was critical of the Syrian government's tight rein over the press. The prime minister, on the basis of proposals submitted by the information minister, "decides who can be a journalist," the organization said. "... The Baath Party continues to maintain a tight grip on all radio and TV broadcasting, while the print media have no choice but to relay what the regime says."
Although a few publications have been launched in recent years not under government control, each publication must be approved by the information ministry and intelligence services before it is issued, Reporters Without Borders said.
A handful of reporters have been detained, some briefly, in the midst of the unrest sweeping North Africa and the Middle East. Last week, four New York Times journalists were released by Libyan authorities after the Turkish government intervened on their behalf.