Safety and security incidents have soared at most B.C.'s prisons over the last few years, according to newly released statistics for 2014 from B.C. Corrections.

The biggest one-year increase was at Surrey Pretrial Centre, where the number of incidents tripled to more than 900 in 2014.

The long-term trend has been steadily up at several other jails.

Safety incidents have nearly doubled by 2014 from five years earlier in Vancouver Island Regional Correctional Centre, North Fraser Pretrial and Kamloops Regional Correctional Centre.

And Alouette Correctional Centre for Women recorded more than three times as many incidents – nearly 700 by 2014 compared to less than 200 in 2009.

Fraser Regional Correctional Centre in Maple Ridge had nearly 1,100 incidents in 2014 and recorded the largest numbers of any sites in B.C. in each of the six years.

NDP MLA David Eby said the statistics he requested are about a year overdue and undercut government claims prison violence was declining.

"I'm incredibly concerned that we were told that violence was trending down when their own numbers show it's trending up and dramatically up," he said.

Eby said a staff shortage in B.C. prisons is a probable factor.

"When prisons are understaffed by guards that means things are less safe for both staff and prisoners," Eby said.

"You don't have anybody screaming about rival gang members being put in the same place at the same time. You don't have anybody just physically present to encourage everybody to be on their best behaviour."

He also cited the overcrowding of prisons from the practice of double-bunking.

"When you have two or three people in a cell as opposed to a single person in a cell that leads to an increase in violence as well."

B.C. government officials say the statistics include not just violence but other safety and security incidents, including inmate illness, threats and contraband.

"B.C. Corrections is housing more inmates with gang affiliations and mental health issues," Public Safety Minister Mike Morris said. "The potential for violence is an unfortunate reality."

Once the new Okanagan Correctional Centre is completed later this year near Oliver, he said, the B.C. Corrections will have added nearly 800 cells since 2008.

Morris said 440 more corrections staff have been added since 2007 and more than 240 new full-time correctional officers will be added for the Okanagan jail.

There were four deaths in B.C. correctional facilities in 2015 – three at Kamloops and one in Surrey – and a total of 26 deaths since 2009.

Safety and security incidents by correctional centre.