The noise from underwater bombs exploded by the UK Royal Navy resulted in the death of 19 pilot whales off the north coast of Scotland in 2011, a report from the Department for Environment Food and Rural Affairs has confirmed.
In July 2011, a mass stranding of pilot whales in Scotland saw 39 whales stranded on the beach. Out of the 39 beached whales 19 later died.
The report argues that the explosions could have damaged the hearing and navigational abilities of the whales.
It stated that the navy exploded three 1,000lb bombs in the 24 hours before the mass stranding.
Later, the navy also fired a fourth 250lb bomb after the stranding had begun.
A statement in the report read: "The magnitude, frequency, and proximity of the multiple detonations in the day prior to the stranding, and the single high-order detonation shortly after the beginning of the mass stranding, were plausible sources of significant disturbance to any neighbouring marine mammals."
In addition, it stated that the fourth bomb might have forced the whales to move further inland.
The report has recommended enhanced monitoring prior to such bombings, pointing that the navy's visual checks were insufficient.
Andrew Brownlow, the lead author of the report said: "We have suggested mitigation strategies, which will hopefully reduce the plausible risk from these types of high-energy detonations on marine life.
"It is hoped they will be taken on board."
Meanwhile, responding to the report, the Scottish National Party (SNP) has asked the Ministry of Defence to provide assurances that no more bombs will be exploded underwater in Scottish seas.