Ruto, a member of the ODM former opposition party, was education minister in the current coalition government, but is currently suspended over corruption charges.
Industrialisation Minister Kenry Kiprono, radio executive Joshua Arap Sang and Ruto have been named in an ICC summons on charges of murder, deportation, persecutions and torture.
The ICC is to issue summons for Kenyatta and former police chief Mohammed Hussein Ali who are accused of murder, deportation, persecutions and rape.
Kenyan paper The Daily Nation reported on Wednesday that security was tight in the lead up to Moreno-Ocampo's announcement.
Kenya announced it will set up a special local court to try those involved in the violence in the aftermath of the 2007 elections, two days before the International Criminal Court in the Hague said it would announce the names of six key suspects.
The ICC took charge of trying the perpetrators of the unrest after Kenya failed to set up a local court.
It is unclear whether Kenya intends to take back the trial of the suspects from the ICC or whether the local tribunal will complement the ICC.
Lawmakers last year rejected a bill aimed at establishing a local court, which would have required a constitutional amendment, saying it could be prone to political interference.