LONDON (AP) — Oil and gas companies operating in the North Sea have been warned to improve safety after a spike in accidental leaks and serious injuries to workers on offshore platforms.

As the US faces years to complete the clean-up of the Gulf of Mexico spill, the British government's work safety agency ordered companies drilling in British waters to clean up their records — or else.

The Health and Safety Executive reported that there were 85 incidents in 2009/10 where hydrocarbon was accidentally released — gas escapes considered "potential precursors to a major incident" — compared to 61 the year before.

The agency also revealed that there were 50 major injuries in 2009/10, up from 30 in the previous year, among 27,000 workers and an average of 42 over the past five years.

In total there were 443 "dangerous occurrences," which included equipment failures and well problems.

The Health and Safety Executive did not name the companies involved, citing its role to provide overall trends on workplace safety, but it has the power to impose a range of sanctions from enforcement notices to prosecution.

"This year's overall health and safety picture is simply not good enough," said Steve Walker, head of the Health and Safety Executive's offshore division. "We will continue to take a tough line on companies who put their workers at risk."

The hydrocarbon leaks raised the greatest alarm, because they have the potential to trigger a bigger disaster, such as the last major incident in the North Sea — the 1998 explosion on the Piper Alpha rig that killed 167 workers.

Hydrocarbon leaks can be caused by a number of factors, including worn out equipment, corrosion, worker error and so-called "vibration fatigue" — structural damage from continued use.

The report, which provides provisional statistics ahead of a full annual review later this year, did not give any detail on how the North Sea incidents might have occurred, but Walker noted the aging equipment used by many operators.

The industry "must up its game to identify and rectify the root causes of such events," he said. "The challenge to improve safety will be ever greater as more offshore installations exceed their original design life."

Oil & Gas UK, an industry representative organisation, said reducing the number of hydrocarbon releases "remains a top priority," while noting that the 2009/10 figures looked worse against a record low in 2008/09.

"It is a a key focus of the industry's absolute commitment to continuously improving process safety standards," said Robert Paterson, director of health, safety and employment for Oil and Gas UK.

The Health and Safety Executive collates the data from company reports on incidents. BP, which is the biggest operator out of around 60 players in the North Sea, declined to give details on its own statistics for the period, but said it "benchmarks well against other North Sea operators in terms of its overall safety performance".

"In terms of major injuries, for example, BP's performance in 2009 was significantly better than the average and we continue to strive towards our ultimate goal of zero," it said in a statement. "Over the last few years we have had a strong focus on reducing hydrocarbon spills and have made major improvements in this area."

In some positive news, the report found there were no fatalities for the third consecutive year. The agency monitors offshore platforms so the data did not include the deaths of 16 people in a helicopter crash and a worker killed on a diving support vessel.