San Sebastian, Spain  - Spanish police Tuesday detained four suspected members of the militant Basque separatist group ETA, police sources said.

The two men and two women were held in their homes in San Sebastian, Pasaia and Intxaurrondo in the Basque region.

They were suspected of supplying ETA with information about people who could be targeted by attacks. Police searched the suspects' homes.

Around a dozen ETA members have been detained within a month, including its suspected military leaders Mikel Garikoitz Aspiazu alias Txeroki and Aitzol Iriondo, who were captured in France.

Tuesday's arrests came two weeks after suspected ETA members killed businessman Ignacio Uria in Azpeitia in the Basque region.

ETA has killed more than 820 people in its four-decade campaign for a sovereign Basque state. (dpa)