Two teenagers have been arrested over accusations they used social media to organise robberies in Melbourne's south-east.

Police executed warrants at homes in Cranbourne, Dandenong and Pakenham on Tuesday night before arresting a 17-year-old Cranbourne teen and 19-year-old Pakenham man.

Phones and a vehicle were seized. Credit:Glenn Hunt

A number of allegedly stolen phones were seized, along with a vehicle.

The arrests follow a police investigation into a number of robberies over the past few weeks that police believe were arranged using social media.

The 17-year-old boy has been charged with a number of offences, including multiple accounts of robbery and theft. He will appear at a children's court.

The Dandenong man is expected to be charged on summons with robbery and theft-related offences.

Police anticipate further arrests will be made.