Germany's gas stocks have fallen to a "worrying" level, an economy ministry spokeswoman said Wednesday, fearing the tensions between Ukraine and Russia put further pressure on energy supplies. 

"Of course we are monitoring the situation of the storage levels and that is certainly worrying," said the spokeswoman during a regular government press conference, noting that stocks were now at 35-36 percent. A year ago, storage levels were at 82 percent of capacity.