Spanish politicians asked intelligence officials to address Parliament regarding allegations the CIA used Spanish airports to transport terror detainees.
The United Left party wants Interior Minister Jose Antonio Alonso and Alberto Saiz, head of the National Intelligence Center, to appear before a parliamentary committee to discuss the claims.
Alonso told the television station Telecinco Tuesday that proof that CIA planes involved in carrying detainees have landed on Spanish soil would chill relations even further between the two countries. He announced the investigation Tuesday.
According to Spanish newspapers 10 suspicious flights landed at Palma between January 2004 and January 2005, UPI reports.