Explosions rattled seven Spanish cities following telephone warnings from the armed Basque separatist group ETA, a resurgence of violence after months of keeping a low profile since the deadly Madrid train bombings by Muslim militants.
Officials said ETA chose a highly symbolic day for a fresh show of force -- Monday's anniversary of Spain's Constitution, which established a system of regional autonomy that the Basque group rejects.
The nearly simultaneous explosions in coffee shops, parks and other public places slightly injured 18 people. They stretched across Spain, with the apparent message that ETA can strike wherever it wants -- even with security forces on high alert because of five blasts on Friday claimed by ETA.
"Once again ETA has tried to scare us on a special day," Interior Minister Jose Antonio Alonso said. "But today has to continue to be the day of the Constitution, not ETA's day."
The bombs went off in Valladolid, Leon and Santillana del Mar in the north, Avila and Ciudad Real in central Spain, Alicante in the east and Malaga in the south. They came about an hour after two calls from people claiming to represent the outlawed group to the Basque newspaper Gara.
Shortly before midnight another call to Gara warned of a bomb outside the headquarters of the conservative, opposition Popular Party. After a two-hour search that included a bomb-sniffing dog unit, police declared it a false alarm, the news agency Efe said. Police had sealed off streets around the headquarters, evacuated bars and restaurants and closed the nearest subway station, the agency said.
Authorities had time to evacuate the places mentioned in the earlier calls, although in at least two instances the explosions occurred in places not referred to by the callers.
That was the case in the town of Santillana del Mar, where 15 people were hurt by shards of glass or chunks of wood when a bomb destroyed a tourist information booth in a park. Three people were wounded in Ciudad Real when a bomb exploded while authorities were evacuating a coffee shop.
The blasts were apparently calculated to avoid loss of life. One Basque analyst said this showed the constraints ETA faces after the March 11 Madrid train bombings.