Hundreds more people had to wait over 12 hours for treatment in emergency departments across Northern Ireland over three months, new figures have revealed.
The latest statistics show that in March a further 253 patients were waiting more than half-a-day in A&Es compared to January – breaching the Health Minister's targets.
The ministerial goal, set by Edwin Poots, is to have 95% of patients treated in A&E within four hours, and no one to wait more than 12 hours.
The figure jumped from 157 in January to 410 in March.
A further breakdown showed that Antrim Area Hospital had the highest number of breaches in March, with 177 people waiting more than 12 hours.
At Belfast's Royal Victoria Hosptial there were 125 breaches.
However, comparing the figures to March 2013, patients waiting longer than 12 hours dropped by almost 60%, from 1,017 to 410.
The statistics released by the Department of Health also noted the performance at the Ulster Hospital improved – decreasing dramatically during that period from 397 to 85. It was still a jump of 47 cases from 38 in February.
During March, there were a total of 60,334 people needing treatment in casualty departments. This compared with 51,711 in February and 55,302 in January.
The statistics also revealed that 74.8% were treated and discharged, or admitted within four hours of their arrival.
Health Minister Edwin Poots said: "The number of patients who had to wait more than 12 hours increased this quarter.
"This is disappointing, however it still represents a significant marked improvement on the same period in previous years (2,360 in total for the period January to March 2013 and 4,012 in total for the period January to March 2012).
"I find it unacceptable that any patient should have to wait unduly in our EDs and I want to see further improvement in waiting times in the coming months.
"I look to the Health and Social Care Board to continue working with the trusts to achieve this and I would encourage everyone to use urgent and emergency care appropriately to avoid adding pressure on to an already busy system."
Number of patients waiting 12 hours or more in A&E departments in Northern Ireland.
October 2013: 77
November 2013: 82
December 2013: 165
January 2014: 157
February 2014: 271
March 2014: 410