Mandurah Forum says at no point were customers or retailers at risk during a gas leak outside the centre.
A Mandurah Forum statement said management was made aware of an isolated gas leak that occurred just outside the centre on Tuesday afternoon.
ATCO Gas isolated the surrounding area and all works were stopped.
The leak has been contained and the area has now been deemed safe by the Department of Fire and Emergency Services and ATCO Gas.
"As always, the safety and wellbeing of our customers, retailers, team members and the wider community is of paramount importance to us," said a Mandurah Forum spokesperson.
"The leak was outdoors within a construction area and at no time was gas detected inside the centre.
"The incident was monitored closely by the centre management team and at no point were any customers, retailers or team members at risk.
"The leak was the result of a gas line being hit by contractors who reported the incident immediately to ATCO Gas."