The British offshore oil and gas sector is not where it needs to be in terms of preventing releases, industry body Oil & Gas U.K. said in a report.

Oil & Gas U.K. published its annual safety report Thursday, which found there's been a 49 percent reduction in the number of reportable releases in the three years ending March 2013. That narrowly missed a 50 percent industry target.

Robert Paterson, health and safety director for the group, said the industry is working with regulators on preventative strategies to ensure targets are met. Nevertheless, Oil & Gas U.K. found the rest of 2013 beyond March saw an overall increase in the number of releases and a slight increase in the number of injuries offshore.

"Despite the ongoing and encouraging decrease in major and significant releases over the last year -- the industry is not yet where it needs to be," he said in a statement.

The group said the industry's health and safety record was mixed. Safety indicators in particular have deteriorated recently, it said.

Four workers were killed in a North Sea helicopter accident in August.