Three Spanish journalists have gone missing in the northern Syrian city of Aleppo, the scene of fierce fighting between regime and rebel forces, including those of Islamic State (IS).

The men were named by the Spanish Federation of Journalists as Antonio Pampliega, José Manuel López and Ángel Sastre.

Elsa González, the president of the association, told Spanish national television they had entered Syria from Turkey on July 10 and were last heard from two days later.

Aleppo is currently carved up between regime and rebel forces. IS, which has kidnapped and killed a number of western journalists, is known to be outside the city and controls parts of the countryside to its north and east.

Sastre is an experienced war correspondent who regularly works with the Spanish television network, Cuatro, radio station Onda Cero and the daily newspaper, La Razón. In October 2013, he spent a month reporting from Aleppo with Pampliega, also a reporter, and López, a photojournalist.

López has spent 11 years working as a photographer, and has been a freelancer in countries such as Afghanistan, Iraq, Palestine, Kosovo and Iran since 2010.

Spanish diplomatic sources confirmed that contact had been lost with the three men. González said it was not known if they were together.

The spate of kidnappings has discouraged western journalists from going to Syria to cover the country’s civil war. Almost no western reporters have visited the country since IS began killing foreign journalists and aid workers it took hostage. The group also has generated cash from collecting ransoms for European journalists.