UPDATE: Authorities probe plane crash on Melbourne runway

Authorities are still probing what caused two light planes to collide on a Melbourne runway today.

A man and a woman, both in their 20s, and a third person were taken to Monash Medical Centre with minor injuries after the crash at Moorabbin air strip.

Two other people are still being monitored by paramedics.

An Ambulance Victoria spokesman says the planes were believed to have been taxiing down the airport runway when they crashed.

Crash investigators are still looking into the matter.