In the latest incident, which took place on Monday evening, nine Algerians escaped from a holding centre in Murcia, a region in the south east, police said.
Spain has seven migrant detention centres for holding people living in the country illegally as officials decide whether or not to deport them.
But there have been a growing number of riots and break-outs as migrants protest their detention in what critics say are prison-like conditions.
A regional spokeswoman said migrants had set light to paper and clothing "to attract attention" and had then attacked police who came to the scene, sparking a confrontation in which nine officers were slightly injured.
Last month, there were two other breakouts from the same centre, with more than 70 migrants fleeing. There have also been similar protests at centres in Madrid and Barcelona in recent weeks.
In one incident in Madrid on October 18th, dozens of migrants climbed onto the roof of the facility - a former prison - spending the night there and unfurling a banner reading "freedom".
Both Madrid and Barcelona have been governed since June 2015 by citizens' platforms backed by far-left party Podemos, which wants these centres closed.
Critics say that steep public spending cuts imposed by Prime Minister Mariano Rajoy's conservative government have worsened conditions at the centres.
Police union SUP says many facilities are dilapidated and have insufficient staff. It says centres in the south, for instance, flood when it rains to the point that detainees have to roll up their trousers to the knee.
Javier Monje, SUP's spokesman in Murcia, called on Tuesday for the centre to be closed.
"It cannot stay open a minute more," he told AFP, pointing out that police at the centre were under equipped.
In an interview published last month in online daily eldiario.es, Ramiro Garcia de Dios, the judge in charge of overseeing Madrid's migrant centre, alleged police impunity was also rife.
Spain is not the only country to have been hit by such allegations.
Rights group Amnesty International has also accused Italian police of mistreating migrants.