Defence Minister Raul Jungmann said the soldiers and national guard officers would stay until calm was restored.
Criminals ran amok in the south-eastern city after police stopped patrolling on Saturday in a row over pay.
Brazilian TV has broadcast scenes of looting, shootings and carjackings.
Banks, schools and public health centres remained closed on Tuesday, as were most shops.
Buses returned to the streets but officials said services would stop by the evening.
"The armed forces are on the streets," Mr Jungmann said after talks with officials in Espirito Santo state.
"We are determined to restore peace, order and tranquillity in Vitoria and wherever else necessary."
The troops have been caught up in clashes between residents opposed to the strike and relatives of the striking officers protesting outside police barracks.
The relatives have rallied in front of police stations because the military police officers themselves are barred from protesting.
The officers are demanding better pay, including extra pay for night work and danger money.
Brazilian media said about 70 people had been killed since the strike began.
More than 1,000 troops are patrolling the streets of the Brazilian city of Vitoria after a police strike led to a crime wave that has left dozens of people dead.