BERLIN (AP) — Two Israeli agents operating in Germany had their cover blown by a suspicious retiree after their car became stuck in the mud by a northern canal, police said Tuesday.

Police in Neumuenster were alerted Dec. 17 to "suspicious people near the canal" by the mayor of nearby Quarnbek, who received a call from an elderly woman after she confronted the two but didn't believe their story that they were scouting the area for a summer sailing regatta.

When officers arrived, the men "immediately identified themselves as being from whatever security service," said police spokesman Rainer Wetzel, adding "I don't know if Mossad was explicitly mentioned."

The armed agents with diplomatic status were there to monitor the delivery of a new German-built submarine bought by Israel and were able to avoid any trouble by producing all documentation necessary.

"Everything was checked and everything was in order," Wetzel said, and police and firefighters helped free their car from the mud.

"I think it was embarrassing for them," Wetzel said.

German broadcaster NDR cited the mayor of Quarnbek as saying he has sent a bill for 1,263.01 euros ($1,392.85) to the Israeli Embassy for the use of the small town's services, but hasn't yet received a reply.

Emmanuel Nahshon, spokesman for the Israeli Foreign Ministry, said he had no comment.