Unexploded wartime bomb found in Nauru detention centre

An unexploded wartime bomb has been found in the section of the offshore processing centre on Nauru that detains children, pregnant women and families, raising serious questions about whether the site is safe to hold asylum seekers.

Internal emails from Nauru, obtained exclusively by Guardian Australia, reveal that after heavy rainfall last week an unexploded artillery shell was found next to the “recreation tent”, which serves as a primary school for asylum seeker children. The email states that another shell was found inside a residential area inside the camp where children and families reside, but Guardian Australia understands the second sighting later proved incorrect.

The internal emails say that the chance of the bomb detonating was “very slim”, but also raises concerns that the site was not properly assessed for unexploded ordnance before families and pregnant women were transferred to the site. The bomb was a Howitzer artillery shell from the second world war.

“No one has been able to give assurances the area OPC3 is located on was adequately checked for UXOs [unexploded ordnance],” the email says.

The shell was found on 15 April and were eventually removed from the site after an exclusion zone was set up.

The email continues: “In the case of Nauru, the physical risks are compounded by the potential trauma of people who are fleeing war torn countries, to now find explosives are being uncovered in the grounds of the refugee camp they’ve been involuntarily sent to.”

The discovery of the bomb at the family camp has subsequently been confirmed by a number of sources and Guardian Australia understands that unexploded bombs have been found before in detention centres on Nauru.

A spokeswoman for the Immigration minister, Scott Morrison, confirmed that the minister had been briefed about the unexploded bomb. She said the bomb was subsequently deemed to be “inert” and some asylum seekers were moved to other sections of the detention centre at an appropriate distance from the exclusion zone.

As a result of the event, the department will complete “a specialist survey company to review the need for a more detailed UXO survey”, she said.

Morrison’s office did not respond to questions about what measures were taken to assess the site for unexploded ordnance before asylum seekers started being transferred last year.

The risks of unexploded ordnance on Nauru, which was occupied by Japanese troops during the war, are well documented. In 2010 the Australian Department of Defence sent a detachment of troops to the Pacific island state to assist with a program to locate unexploded bombs as part of “Operation Render Safe”, an ADF mission to assist pacific nations with the threat of UXOs.

“Unexploded ordnance is a troublesome legacy of the second world war and has been an ongoing problem for the island nations of the south-west Pacific,” Lieutenant General Evans of the ADF said at the time.

Unexploded ordnance is also a significant risk at the offshore processing centre on Manus. A leaked planning report for the second detention centre on Manus, now under construction, determined there were serious risk of unexploded ordnance at the site, but was unable to comprehensively document the risks.

There are now 179 children detained on Nauru, the majority in OPC3, and 313 women.