Madrid ? Reports of alleged CIA use of Spain as a stopover point for transporting suspected Islamic terrorists spread Wednesday to the Canary Islands, where the regional government said it had asked Madrid to explain if airports there were also used for covert missions.

The Spanish archipelago off west Africa joins the Mediterranean island of Mallorca in the controversy.

Interior Minister Jose Antonio Alonso said Tuesday a judge is investigating reports that at least 10 flights landed in Mallorca as part of the CIA’s program of “extraordinary rendition,” in which suspected terrorists are taken without court approval to third countries for questioning and possibly subjected to ill treatment.

The Canary Islands government said Wednesday that in May it had asked the central government to explain local newspaper reports that suspected CIA planes had made stopovers five times on the island of Tenerife between March 2004 and May 2005.

“But we never got an answer back, or just a vague answer that the government had no evidence. Now we want to ask again for those explanations,” Miguel Becerra, a spokesman for the Canary Islands government, said in a telephone interview.