Violent clashes between Christian and Muslim refugees in Germany has led to calls for them to be housed separately.

Deputy head of Germany's police trade union, Jörg Radek, told the country's Die Welt newspaper that police "have reached their absolute breaking point".

"Our officials are increasingly being called to confrontations in refugee homes," Radek said. "When there are 4,000 people in a home which only actually has places for 750, this confinement then leads to aggression where even a tiny thing like the corridor to the toilet can lead to violence."

Separating refugees on religious grounds "makes perfect sense," Radek added. "We must do everything we can to prevent further outbreaks of violence."

On Sunday night, 14 people were injured in clashes that broke out at a "temporary centre housing 1,500 refugees in the town of Calden in central Germany. According to local media, it took police several hours to end the violence, during which Albanian and Pakistani refugees fought each other with clubs.

Last Friday, 200 Syrian and Afghan migrants attacked one another over a dispute over toilets at an asylum centre near Leipzig.

Germany is expecting to take in at least 800,000 refugees this year, and is the recipient of the largest number of asylum applications in Europe. However, President Joachim Gauck warned on Sunday that there are limits as to how many refugees the country can manage.

"We want to help. We have a big heart. However, there is a limit to what we can do," he said. "Our ability to take in people is limited, although we don't know yet where those limits are."

In the wake of Gauck's comments, a government spokesperson defended the decision to welcome significant numbers of refugees. "The German government and the chancellor are convinced that protection has to be given to those who need it, whether they are persecuted for political reasons or fleeing war," spokesman Steffan Seibert said.