IAAF urges Beijing action over world championship crowds

The Aug. 22-30 championships will be the first major athletics event held at the Bird's Nest stadium since the 2008 Olympics, when big crowds packed the iconic venue for both the heats and the evening finals.

Large numbers of empty seats, especially during the heats on the morning of competition days, have long been a problem for the International Association of Athletics Federation (IAAF)'s biennial showpiece event.

That Beijing had already proved it could get seats filled was a major attraction when the Chinese capital bid to host the event but Diack said ticket sales were not going as well as he had been led to expect.

"I myself visited Beijing for the 'One Year to Go' promotional ceremony in August 2014 and I was in Beijing again in March and again in April 2015 to support the promotional effort," the IAAF president said in a news release.

"On both occasions I reiterated the need to invest properly in the promotional efforts to secure what had been promised to us by the Chinese authorities for this event - 100 percent capacity for the evening sessions and 30 percent for morning sessions.

"But at the moment, we see that some evening sessions are still around 50 percent of capacity, so we need to work very hard in the remaining weeks. We have no time to lose now."

Organisers of sporting events in Beijing have in the past bused in groups of spectators to fill empty seats when ticket sales have not gone as well as expected.