Qatar has launched an investigation after heavy rains exposed poor construction in the oil-rich country set to host the 2022 FIFA World Cup.

The state-run Qatar News Agency says five firms are under investigation, without elaborating. The statement says the probe was launched by Prime Minister Sheikh Abdullah bin Nasser bin Khalifa Al Thani, who also serves as interior minister.

The report late Wednesday said that "parties responsible for dereliction or negligence, whether governmental or private, will be held accountable."

A year's worth of rain on Wednesday deluged Doha's Hamad International Airport, the home of Qatar Airways. The airport, which cost at least $15 billion to build, saw rain pour through at least one portion of its roof.

Rainwater also flooded streets and shut down some stores in Doha.