Police said the migrant accommodation had been deliberately set on fire overnight while 26 people were inside.

"The fire started from two places in the corridor," a police spokesman said. He added that the blaze was being investigated by a team of officers from the State Protection Office and the homicide commission.

The targeted building comprises several apartments housing refugees as well as homeless people. Five residents were injured in the blaze and taken to hospital, while the other occupants escaped unharmed. Police said the cost of the damage came to around 2,500 euros ($2,790).

Erbach Mayor Achim Gaus said he couldn't account for the attack because there had been no major protests against refugees living in his city.

Increasing attacks on homes

According to Germany's Federal Police Office, more than 700 cases of attacks against migrant accommodation have been registered so far this year. These incidents range from swastikas, spray-painted outside the door, to arson and other forms of property damage.

One case in particular garnered worldwide attention. In February, a refugee home in the eastern town of Bautzen was set on fire while onlookers applauded and chanted right-wing slogans.

The city was in the negative spotlight again this week after violent clashes broke out there between refugees and local right-wing protesters.

In 2015, there were 1,047 attacks on planned and completed refugee shelters across Germany, and authorities warn the tally could be even higher for 2016.

nm/sms (AFP, dpa)