MADRID (AP) - Spain said Wednesday that it is trying to establish what happened to three Spanish freelance journalists who went missing around the embattled northern Syrian city of Aleppo as news emerged that a fourth journalist, a Japanese national, has gone missing in the war-torn country.

Justice Minister Rafael Catala told Spain's Cadena SER radio the government had no news regarding the three Spaniards and will contact the government in Damascus over the case. He could not say if authorities are treating their disappearance as a kidnapping.

Spanish Foreign Minister Jose Manuel Garcia Margallo urged ``maximum discretion'' in the case but called for "tranquility,'' saying similar situations in the past had ended well for Spain.

With the rise of the Islamic State group, most media organizations have opted to stay away from coverage inside Syria because of the unacceptable risk level. Over the last year, it has become rare for any foreign journalists to go into northern Syria, where a myriad of Islamic groups and the more extremist IS and al-Qaida group rule.

A Spanish journalism association first reported on Tuesday that the three _ identified as Antoniu Pampliega, Jose Manuel Lopez and Angel Sastre _ were missing since July 13. They had traveled to Syria, presumably together, to report on the country's long-running civil war.

“An effort has been underway since then to search and locate them,'' a statement from their families said.

The three are the latest journalists to become ensnared in the world's most dangerous assignment for reporters. A fourth journalist, a Japanese freelancer, has also been reported missing in Syria where he was last heard from one month ago.

It is not known why Jumpei Yasuda, who has been reporting on the Middle East since 2002, has not been in contact. Yasuda was taken hostage in Iraq in 2004, with three other Japanese, but was freed after Islamic clerics negotiated his release.