Las Palmas almost stunned the home side just before the break as Calleri rattled the upright from close range.
Barca's win keeps them top of La Liga, ahead of Sevilla by seven points, whereas the 3-0 defeat leaves Sunday's visitors level on points with Eibar, who occupy the final relegation spot.
The violence led to an emergency board meeting at the Nou Camp, where it was decided they would put in an official request to have the match postponed.
"I believe that I can continue to go to selection because there are a lot of people in Spain who are in total disagreement with the facts that are happening today in Catalonia and who really believe in democracy", said Piqué. Las Palmas enjoyed the greater share of possession and hit the post through Jonathan Calleri, with Barca's only advantage appearing in a 4-0 yellow card count at the break.
"I made a decision to play behind closed doors because we believed that the image of a football match being played in a completely empty Camp Nou.would have been a way of showing how we utterly reject the exceptional and inadmissible situation going on in Catalonia".
"It was my worse experience as a player".
"And if we did have to play it, then not behind closed doors".
Barcelona defender Gerard Pique, one of the most outspoken players defending the referendum, called Sunday's incidents "shameful".
The defender (30 years) has explained that the players have chose to play the meeting after that their management has tried in vain to obtain the postponement of the match.
Barca tried to have the game postponed but were told by La Liga that there were no grounds to do so in the interests of safety.
Barcelona's Camp Nou, Europe's largest stadium, is often used as a rallying point for Catalan nationalists.
"Today, Las Palmas pay a visit to Camp Nou, on an unprecedented date for our country, on the day that the Catalan government has set a referendum outside the Spanish legal framework", a statement read.
"We were aware of what happened here today, we don't live in an igloo", Barcelona coach Ernesto Valverde said. The Canary Islands club said the club did not want to limit itself to being a "quiet witness at an historic crossroads".