"This protest is meant to show solidarity with the two journalists and protest the threats facing the freedom of media and movement in Libya," Farah Shandoul, who works for a state-run radio station in the city of Tataouine, told The Anadolu Agency.
"We staged this protest here to show the symbolic nature of the place, as the kidnapped Tunisian journalists entered Libya through Ras Ajdir," he said.
"And we hope they will return home safely through it as well," he added.
Sefian Shawarbi and Nazir al-Qatari were both abducted in Libya last September while working for Tunisia's privately-owned "First" TV channel.
Last Thursday, ISIL group in Libya's eastern town of Barca announced it had executed the two journalists, according to a statement disseminated by Jihadist websites that included photos of the two men.
The purported ISIL statement, however, has not been independently verified, while the Tunisian government has yet to produce any clear information regarding the two men's fate.
Around 30 journalists gathered at the border terminal on Monday to demand to know the two men's fate.
"This protest is being staged by reporters from Tunisia's southeast to show support for the two journalists," Abdel-Salam Amin, secretary-general of the independent Journalists Syndicate in the southeast, told AA.
"We chose the terminal to host the protest in order to get our message across," he added.
Libya has largely remained in a state of lawlessness since the 2011 ouster and death of strongman Muammar Gaddafi.