Spanish Becoming Jihadis Second Language
Counter-terrorism forces in the country have warned about an "increase in allusions to our country" in recent texts, videos and propaganda produced by ISIS.
The jihadis have been increasingly writing in Spanish and even analysing Spain's election results, which authorities believe "increases the possibility of a terror attack in our territory".
A statement written in Arabic in July by the ISIS-linked Wafa Media Foundation said: "Anywhere you consider a valid target to punish Spanish criminals, by any means."
The group also urged people living in the north African area of Maghreb - Morocco, Tunisia, Mauritania and Libya - to attack Spanish citizens.
Spanish ISIS researchers said they have seen a worrying rise in references to Spain by jihadis.
They said more texts and statements are being translated into Spanish which "give our country more propaganda relevance and increase the possibility of terror attacks in Spanish territory".
More and more jihadis are speaking Spanish, they added.