The opening ceremony of 2016 Rio Paralympics in Maracana, Sept 7. [Photo/Xinhua]

More than 4,400 athletes from 160 countries and regions will compete at the Rio Paralympic Games, which officially opened at the Maracana Stadium on Wednesday.

The figure includes two refugees, who will participate under the International Paralympic Athletes flag, the International Paralympic Committee (IPC) said on Wednesday.

Of the 4,432 athletes registered for the September 7-18 Games, a record 1,621 are women - 12% more than London four years ago and more than double the number that participated in Atlanta 20 years ago.

The overall number of athletes in Rio eclipses the 4,302 participants that took part in London and the 3,951 who were registered in Beijing in 2008.

The high participation level comes despite the late withdrawals of Comoros and Liberia, and the absence of Russia.

IPC president Philip Craven said organizers had overcome many obstacles, such as budget cuts and slow early ticket sales amid Brazil's worst recession in decades.

"Two weeks ago I said we faced unprecedented circumstances and since then we've seen unprecedented teamwork," Craven told a news conference.

"The feeling coming out of the athletes village is that athletes are happy. The thing to remember is athletes perform best when they are happy and I only saw happy athletes in the village, and that's all right for me."

Since the Olympic Games closing ceremony on August 21, ticket sales have risen from 300,000 to almost 1.7 million, Craven said.

Organizers are now hoping the to overtake the 2.4 million tickets sold at the Beijing 2008 Games.

"These are going to be the people's Games. You cannot come to a more passionate country for sport, but you've got to engage with the hearts," Craven said.

"I think that we've seen from the massive increase in the ticket sales that the Cariocas [Rio residents] and the Brasileiros are ready for these Games and they want more after the Olympics and they particularly want to see the Brazilian athletes."

"It's always very very important to have a highly successful national team coming from the country where the Games are taking place."

Craven said a record 1,500 athletes would be tested for doping during the Rio Paralympics.

The Games will be broadcast to 154 countries and regions - 39 more than in London.