WhatsApp is blocked throughout Brazil following a judicial order requiring cell phone operators in the country to disable the messaging app for 48 hours.

The order a criminal court in Sao Paulo state went into effect at midnight.

The order resulted from criminal proceedings that haven't been made public.

In a statement, the Sao Paulo court said the messaging service had failed to heed two prior judicial orders earlier this year. For that reason, the public prosecutor's office requested the app be blocked, the statement said.

Mark Zuckerberg, who heads WhatsApp's parent company Facebook, reacted with a Facebook post calling it "a sad day for Brazil." He says the company is working to get the block reversed.