Bangladesh captain Mashrafe Mortaza refused to write off his side's chances of qualifying for the World Cup semi-finals despite a 48-run loss to reigning champions Australia at Trent Bridge on Thursday.

"I think still you never know," Mashrafe told reporters. "I think, we have still three matches left. We have to play hard and then let's see."

"And it's going to be difficult for sure, even if we win all those three matches," added Mashrafe, whose side next play strugglers Afghanistan in Southampton on June 24.

Only the top four at the end of the 10-team round-robin group phase will advance to the knockout stages and Thursday's defeat left Bangladesh, who have beaten both South Africa and the West Indies, in fifth place.

They are two points behind fourth-placed India, having already played two games more than Virat Kohli's men.

The current top four of Australia, New Zealand, England and India are starting to look uncatchable even though there are several rounds of group matches left.

"I think at this stage we thought a few matches would have been lost by the top four and the tournament would then have gone in a different way," said Mashrafe.

"But there are still a few matches left, you never know. Let's see."

It might have been a different story for Bangladesh in Nottingham had David Warner not been dropped off Mashrafe's bowling on 10.

The opener capitalised to score 166 in a total of 381-5 that effectively put the match beyond the reach of Bangladesh, who nevertheless responded with a gutsy 333-8 featuring Mushfiqur Rahim's unbeaten century.

"We knew we have to pick up wickets," added Mashrafe, the sole survivor from the Tigers' celebrated 2005 One-Day International win over Australia in Cardiff.

"If not then it's going to be very difficult, which is exactly what happened. David Warner is batting so well."