Madrid - Bomb and arson attacks believed to be the work of the Basque separatist ETA organisation damaged two train stations in Spain's northern Basque Country early Saturday, but injured no one, security officials said.

A bomb exploded shortly after midnight at Berriz train station near Bilbao, causing considerable damage. Officials said that there had been no warning, and no one claimed immediate responsibility.

Two hours later, masked attackers fire-bombed Amorebieta station some 20 kilometres away. Both stations were deserted.

ETA usually warns in a phonecall shortly before any bomb attack. The rail line serving the two stations, run by Eusko Tren, links Berriz with the cities San Sebastian and Bilbao.

The attacks came the day of a planned - but banned - regional referendum on Basque self-determination. The ban was ordered in September by the Constitutional Court. The referendum had been planned by the regional government.

Basque nationalists accuse the Spanish government and judiciary of using the fight against ETA as a pretext to block any discussion on independence.

ETA is blamed for more than 820 deaths in its four-decade campaign for a sovereign Basque state. (dpa)