MADRID – Madrid city hall apologized Monday to parents for exposing their children to a violent puppet show, but says jailing the puppeteers for allegedly praising terrorism was disproportionate.

The two puppeteers were detained without possibility of bail Friday for using a sign saying, “Long Live Alka ETA,” in a word-play reference to Spain’s armed Basque group ETA and al-Qaida.

The satirical theatre piece also featured the hanging of a judge’s effigy, the stabbing of a nun with a crucifix and police beatings, prompting parents attending with children to complain.

The show was commissioned by the city as part of Carnival celebrations.

Madrid Mayor Manuela Carmena, 71, said the show’s content was inappropriate for children but that jailing the puppeteers without bail was incomprehensible.

Praising terrorism has been a crime in Spain since 1995.

Carmena, a retired judge, said the town hall had made a serious error by being unaware of the show’s content and advertising it as suitable for all ages. She said there would be an investigation.

City hall initially presented a legal complaint against the puppeteers but was now studying withdrawing it.

Spain’s Terrorism Victims Association said Monday it was taking legal action against the puppeteers, the mayor and the city’s cultural councillor, Celia Mayer. Spain’s acting ruling conservative Popular Party called for Mayer’s dismissal.

Mayer said in a statement the suits were part of a campaign to discredit Carmena’s leftist city government.

Carmena became Madrid’s first left-wing mayor in 24 years on taking office in June.