Twin girls attend a float parade during the 15th Mojiang International Twins Festival in Mojiang Hani Autonomous County, southwest China's Yunnan province, Nov. 28, 2019. About 1,000 pairs of twins from around the world took part in a float parade in Mojiang Hani Autonomous County on Thursday. (Xinhua/Yang Zongyou)

Thousands of twins packed two-by-two into a stadium in Sri Lanka's capital on Monday - so many that officials struggled to count them in time to prove they had organized a record-breaking gathering.

Huge queues built up at the open-air venue in Colombo as sets of siblings waited to get their birth certificates checked. 

"The counting is still going on. We will submit the final count and the documentation back to the Guinness World Records committee and I am confident we will be informed in writing that we hold the record," Upuli Gamage, co-organizer of the event, told the crowd.

There was no immediate comment from the Guinness organization on whether the event had met the requirements to claim the record.

Many of the twins - including children, pensioners and police officers - had traveled for hours to attend the event, which had Sri Lanka's Prime Minister Mahinda Rajapaksa as the guest of honor.