The organizers of the Copa America expressed concerns over poor attendance at initial games on Monday and said they must correct errors in the ticketing process to ensure more fans have access to matches in this month's tournament in Brazil.

The issue cropped up after Friday's opening match between Brazil and Bolivia saw empty spaces in the stands and the controversy grew on Monday. The 65,601-capacity Morumbi stadium was filled with only 47,260 spectators, even though organizers had said the game was sold out.

Fans trying to buy tickets for Brazil games in advance faced difficulties and the Local Organizing Committee said they had held some tickets back that later went unsold.

The problem of poor sales was particularly evident on the second and third days of the tournament when three of the four games had attendances below 20,000.

Just 11,107 fans turned out for the match between Peru and Venezuela in Porto Alegre, and 13,611 watched Uruguay's 4-0 win over Ecuador in Belo Horizonte.

Only 19,162 people were in the 78,000-seat Maracana stadium to watch Qatar draw 2-2 with Paraguay.

Some fans blame the organizers for mishandling ticket sales while others blamed saturation with the ongoing edition of the Copa America being the third in five years.

Expensive tickets could also be a cause of poor attendance.

Cost of tickets for the Brazil-Bolivia game ranged from 190 reais to 590 reais (about $49-$152), while the lowest for most other games is 120 reais - still a considerable amount of money in the developing nation.