A communication oversight was to blame for almost 100 children being allowed onto the Telstra Stadium ground during a thunderstorm which officials deemed unsafe for AFL players to be out in.

With lightning flashing, players and officials rushed from the ground as the halftime siren sounded with Sydney leading West Coast by 30 points in an the AFL elimination final.

AFL manager of ground operations Jill Lyndsay said the halftime break was extended by two minutes to allow the storm to pass and make it safe for the players.

But while officials were coming to that decision, the children played mini-AFL games while the lightning continued.

The kids were eventually taken from the ground after about five minutes for safety reasons.

"They weren't supposed (to go out onto the field)," Lyndsay said.

"We were in the tunnel down at this end and the kids ran out as soon as the siren sounds.

"As soon as we saw them out there, I was busy obviously dealing with that issue of the team, we immediately called back and got them off the ground as quickly as possible.

"The people managing the AusKick probably should have been mindful of that.

"But it was just an oversight, not being able to liaise with them."

Brought to you by AAP © 2024 AAP