Lewis Hamilton has taken aim at Formula One's bosses for staging the Australian Grand Prix, describing their decision as "shocking".

At least five members of the sport's travelling circus are in quarantine in Melbourne after showing symptoms associated with coronavirus.

A host of sporting fixtures have been cancelled across the globe in response to the outbreak of the deadly disease, with the NBA the latest league to announce it had suspended the season with immediate effect.

"I am really very, very surprised that we are here," said an animated Hamilton.

"For me, it is shocking that we are all sitting in this room.

"There are so many fans here already today. It seems like the rest of the world is reacting, probably a little bit late, but we have seen (US president) Donald Trump shut down the borders from Europe to the US, the NBA has been suspended, yet Formula One continues to go on."

More than 300,000 fans are expected through the gates of the Albert Park venue for this weekend's race.

Asked why he thought the sport's chiefs and its governing body, the FIA, have pushed ahead with the opening round in Melbourne, Hamilton replied: "Cash is king.

"I don't feel like I should shy away from my opinion.

"The fact is we are here and I just urge everyone to be as careful as you can be in terms of touching doors and surfaces.

"For the fans, I hope they take precautions, too. I was walking through the paddock and saw everything going ahead as normal as if it is a normal day, but I don't think it really is.

"I hope the fans stay safe and we go through this weekend and we don't see any fatalities or anything come out in the future."

American outfit Haas have confirmed an additional two staff members have been tested for coronavirus, taking their tally to four. A member of McLaren's team was tested on Wednesday. Both McLaren and Haas are awaiting the outcome of the results, and have been told it could take up to 72 hours.