At least four people including a nine-year-old child have died after a tourist boat collided with a speedboat off the Greek island of Aegina.

The captain of the boat and a male passenger was also identified among those to have been killed in the crash off the popular holiday island.

Nearby vessels had helped to rescue 21 people from the water, four of whom were injured, said the Greek coastguard.

Other people were still missing, Aegina mayor Dimitris Mourtzis told Skai TV.

Officials have estimated that around 15-20 people were on the tourist boat when it crashed en route to the deserted island of Moni.

It was not known how many people had been on the speedboat.

It was not immediately clear what had led to the collision or the nationalities of those involved.

Aegina's proximity to the Greek capital makes it a popular destination for Greeks and foreign tourists alike.