Authorities in Brazil have arrested two policemen in connection with last week's massacre of 30 people on the outskirts of Rio de Janeiro.

The two, Fabiano Lopes and Jose Felipe, were arrested Saturday based on descriptions provided by witnesses to the killings.

The slayings happened last Thursday night in two suburbs in the Baixada Fluminense region north of Rio, which is notorious for its high crime rate. Several gunmen in two cars randomly opened fire on men, women and children.

Rogue police are suspected in the slaughter, possibly in retaliation for the arrest of eight other corrupt policemen suspected in a brutal double murder.

Between 400 to 600 federal security officers are expected to arrive in Rio this week to secure the region.

Some information for this report provided by AP and Reuters.