Officials blame militants for car bomb killing two

MADRID, Spain -- A car bomb allegedly placed by Basque separatists exploded in northern Spain on Friday, killing two police officers and prompting the prime minister to cancel plans to attend a summit in Russia.

A third police officer was severely wounded and five civilians were wounded in the early afternoon attack that shattered windows and set cars ablaze in the town of Sanguesa in Navarra province.

The officers had just returned to their car from a nearby government building when the bomb exploded from beneath their car, authorities said.

There was no immediate claim of responsibility, but Deputy Prime Minister Mariano Rajoy said the bomb was set by ETA, a group that often uses car bombs in its campaign for a Basque homeland in northern Spain and southwest France.

"ETA has murdered once again," Rajoy said in Madrid, vowing to use "all means at our disposal" to fight the group.

Prime Minister Jose Maria Aznar called off his trip to St. Petersburg, where he planned to attend a summit with Russia and the European Union, officials said.

Navarra province borders the troubled Basque region and is home to many Basque nationalists

The explosion came five days after Basque local elections that excluded hundreds of pro-independence candidates allegedly linked to ETA's outlawed political wing.

The last attack blamed on ETA was the Feb. 8 shooting of Joseba Pagazaurtundua, police chief in the town of Andoiain, home to many supporters of the banned Basque party Batasuna.

The pause in violence led to speculation that ETA might be observing a truce like the one it called in 1998. But two weeks ago hooded men identifying themselves as members of the group appeared in a video broadcast on Basque TV and said their fight continued.