The pair had to be separated by striker Pierre Webo after clashing in the 90th minute of the one-sided encounter at the Amazonia Arena. After the match, a furious Cameroon coach Volker Finke vowed to ascertain the cause of the incident, reports Xinhua.
"It's clear we have to find the reasons what's going on because such behaviour is really disgusting. It won't do, it's impossible," Finke said.
Oh africa..SMH...Benoit Assou Ekotto fighting his team mate. pic.twitter.com/HmiLK7Xsd6"— G¡d!££ Râ¿ (@Gidiee_amin) June 19, 2014
Earlier, midfielder Alex Song was shown a straight red card for elbowing Croatian striker Mario Mandzukic in the back.
The result means the 'Indomitable Lions' are eliminated from the tournament despite a group match against Brazil to come.
Cameroon's disastrous campaign follows a series of off-field controversies that blighted their preparations for the event. The squad almost refused to board the flight to Brazil over a pay dispute while their star striker Cameron Eto'o has faced allegations about his personal life.
Eto'o vowed Tuesday to "respond to all accusations" and "reveal names" after the World Cup.
The capitulation against Croatia was Cameroon's sixth straight World Cup loss.
They have managed just one World Cup victory - a 1-0 win over Saudi Arabia in 2002 - since becoming the first African nation to make the tournament's quarterfinals in 1990.