Egypt’s foreign ministry said Friday it was “working around the clock” to secure the release of six of its citizens being held in Libya.

“The six Egyptians are detained in an illegal immigration center in western Libya,” the ministry said in a statement.

The six Egyptian Coptic Christians had traveled to Libya across the border from Egypt “with work permits stipulating their presence only in the east of Libya,” it added.

The ministry said it was “working round the clock” to secure their release and was in contact with Egyptian diplomats based in Tripoli who are pursuing the matter with Libyan authorities.

It also called on citizens not to violate the instructions related to travel to Libya and to fully adhere to declared areas of movement in order to ensure their safety, stressing that the relevant state agencies would continue to put forth maximum efforts to ensure the return of the six citizens.