A protest will take place on Thursday in support of three Al Jazeera journalists captured in Libya in March.

A video on Al Jazeera English’s YouTube channel says Ahmad val ould Eddin and cameramen Ammar Al-Hamdan and Kamel Al Tallou are being held illegally.

According to this article on Al Jazeera’s website, the three were held near Zintan in the northwest of the country and then imprisoned in Tripoli. The broadcaster says it has no information on why the trio are being held.

The National Union of Journalists is joining the protest, which will take place between noon and 4pm in front of the Libyan Embassy in Knightsbridge, London.

“We are demonstrating in support of our Al Jazeera colleagues because it is vital to their safety that attention is focused on their plight at a time when the enormity of events in Libya might cause them to be forgotten,” NUJ general secretary Jeremy Dear said in a statement.