(CNN) -- The head of the U.S. Coast Guard and a congressman planned to travel to the Coast Guard Academy on Thursday to speak to cadets about the discovery this summer of two small hangman's nooses on Coast Guard properties.
Coast Guard Commandant Adm. Thad Allen, seen in a file photo, planned to address cadets on Thursday.
"These are going to be our future leaders. The last thing you want are your leaders not being tolerant," Rep. Elijah Cummings, D-Maryland, told CNN before heading for the academy with Coast Guard Commandant Adm. Thad Allen.
A 6-inch string tied as a noose was found in an African-American cadet's sea bag in July while he was serving aboard the historic tall ship Eagle.
And during race-relations training in August -- set up in response to the first incident -- a white female civil rights instructor found a small noose in her office at the academy in New London, Connecticut.
Initial investigations failed to discover who was responsible. Last week, after the incidents became public, academy superintendent Rear Adm. J. Scott Burhoe ordered the Coast Guard Investigative Service to investigate further.
People found to be involved could be prosecuted under military law, he said in a written statement.
An academy spokesman, Chief Warrant Officer David French, said Burhoe is expanding race relations training to all staff members at the academy, and has contacted the community and the NAACP for assistance.
Cummings said he would have a message for the cadets when he addressed them on Thursday.
"I want to say to them that they should not tolerate it amongst themselves, because they will be judged by their weakest link," he said. "So far we haven't found out who did this, but I think they can help us find this person."
The noose incidents were first reported last week in The Day newspaper in New London.
The reports came amid a rash of incidents around the country involving nooses and their grim symbolism.
The so-called "Jena 6" case began about a year ago when white students in a small Louisiana town hung nooses from a schoolyard tree after black students sat under it.
Last month, two teenagers were arrested in nearby Alexandria, Louisiana, after driving through town with nooses hanging from their pickup truck, the night after a protest march brought thousands of demonstrators to Jena.
In Hempstead, Long Island, a suburb of New York, a noose was found Friday hanging in the locker room at a police station. Community leaders called for an investigation into that incident.
"The noose, to African Americans, is a symbol of hatred and it takes us back to the times when African-American people were being hung from trees for no reason at all," Cummings said. "And so it's a very offensive kind of thing."
The Coast Guard Academy has about 980 cadets, about 14 percent of whom are minorities. African Americans make up about 4 percent of the corps. E-mail to a friend