Spanish police have arrested 16 people, including 12 lawyers, for alleged ties with the armed Basque separatist group ETA.

The Interior Ministry on Monday said the 16 are being charged with membership of a terrorist organization. Twelve are also charged with money laundering and tax fraud.

Besides the lawyers, four treasurers for a group that represents ETA prisoners were arrested.

The ministry said the detained acted as links between ETA's leadership and the group's jailed members.

The arrests were carried out in Madrid and the northern Basque and Navarra regions.

ETA declared what it called a permanent cease-fire in 2011. It's blamed for killing some 830 people in a four-decade-long campaign for a Basque homeland in northern Spain and southwestern France.