The "precautionary code red" lockdown on a Melbourne elementary school has been lifted on Friday morning, but it's not clear why.

Roy Allen Elementary, at 2601 Fountain Head Boulevard, was under lockdown since 9:15 a.m., according to authorities. It was lifted just before 11:30 a.m.

It's not clear what caused the lockdown.

No other details were immediately available.

Check back for more information on this developing story.