Two police hurt in Bilbao blast

ETA injured 100 people in a bomb in Madrid earlier this month

Two police officers have been injured in a blast in the northern Spanish city of Bilbao.

The officers were removing a placard in Echeverria park late on Tuesday which called on members of the Basque separatist group ETA to murder police, when a hidden device exploded, Spanish authorities said.

The banner read: "Police are murderers. ETA, kill them," according to the Spanish Interior Ministry.

The two members of the Basque regional police force were hospitalised but there are no further details on their condition, the ministry said.

ETA is an armed Basque separatist group that has killed more than 800 people in 30 years in a battle to win an independent Basque homeland in northern Spain and southwest France.

Last week the group claimed responsibility for the fatal shooting of a judge in northern Spain and a car bomb in Madrid which wounded more than 90 people, earlier this month.