Spanish police say they have arrested six suspected members of a jihadi cell linked to Islamic State and Jabhat al-Nusra militants during raids in the eastern provinces of Valencia and Alicante and in Spain's North African enclave of Ceuta.

Four of those arrested have Spanish nationality but are of Syrian, Jordanian and Moroccan ancestry. Two others are Syrian and Moroccan nationals living in Spain.

Police said in a statement they began investigating the suspected cell in 2014 and the arrests took place early Sunday. It said the investigation has uncovered evidence that those arrested provided "logistical support that was essential for the maintenance of terror activities" in Syria and Iraq.

The investigation is being coordinated by Spain's National Court in conjunction with state prosecutors and is still going on.