At least a hundred new coronavirus cases in Germany have been traced back to a service held at an evangelical church after the country started to ease lockdown restrictions.

The cases are linked to a service held at the Evangelical Christian Baptist Church in Frankfurt on May 10, Hesse health minister, Kai Klose, told the Deutsche Presse-Agentur (DPA). 

The service took place after the state eased restrictions on worship services on May 1 following Angela Merkel's decision to approve the re-opening of religious institutions, museums and zoos.

Church leaders say they adhered to social distancing guidelines and disinfected the building. 

"We followed all the rules," church elder Wladimir Pritzkau told DPA. 

Klose said health officials have been contact tracing people who attended the church service to find out the extent of the spread. 

Frankfurt health chief Rene Gottschalk told DPA that many of the infections were not serious. 

"Most of them are not particularly sick," he said. 

The church said it was "dismayed" by the outbreak. 

"We are deeply dismayed and sad that the infection has found its way into the community and has spread with great dynamism," it said in a statement.

"Our thoughts and prayers are with all sick and relatives who are going through a difficult time. Our consolation is that many sick people are well on the way to recovery and some have already recovered."