The Sydney offices of Ninemsn were evacuated yesterday so that the Australian bomb squad could open what turned out to be a press kit for Watch Dogs.

Ubisoft sent journalists a copy of the game locked inside a safe which beeped when anyone attempted to open it. Journalists became concerned when they called others newsrooms and discovered no one else had received a similar parcel.

After calling the authorities, the floor was evacuated and staff were sent home early. The bomb squad then scanned the safe, before taking it to the basement to open it, whereupon they discovered its benign content.

Ninemsn condemned the promotion as "misconceived".

"The PR company no doubt got carried away with their creativity and ended up sending us something the bomb squad had to open up," said Ninemsn publisher Hal Crawford.

Ubisoft apologised, and said it had taken steps to avoid a recurrence of this outcome in the future.

"As part of a themed promotion for Watch Dogs, our team in Australia sent voicemail messages to some local media alerting them that they'd receive a special package related to the game," it said in a statement.

"Unfortunately, the delivery to Ninemsn didn't go as planned, and we unreservedly apologise to Ninemsn's staff for the mistake and for any problems caused as a result."

Ninemsn does not cover videogames.