Following recent discoveries of hundreds of bone fragments atop the former Deutsche Bank building, Senator Schumer has asked that forensic experts from the military search the area around ground zero for traces of more than 1,100 victims of the September 11, 2001, attack whose remains have not been identified.

Nearly three years after the city finished removing rubble and remains from where the World Trade Center once stood, Mr. Schumer said recovery operations needed to be expanded to include the buildings along the perimeter of ground zero.

The military unit whose help Mr. Schumer seeks to enlist is the Joint POW/MIA Accounting Command, which is based in Hawaii. The job of JPAC, whose motto is “until they are home,” is to recover the remains of America’s missing war dead.

At a press conference yesterday, Mr. Schumer said he had sent the secretary of defense, Donald Rumsfeld, a letter requesting personnel from the unit be sent to Lower Manhattan. He added that he intended to follow his letter with a phone call today.

About 600 bone fragments, more than 100 of them in recent weeks, have been discovered amid the rooftop gravel of the former Deutsche Bank building as construction workers prepare it for demolition. The building had been showered with asbestos and scarred by the collapsing south tower on September 11. The Lower Manhattan Development Corporation purchased the wrecked building in 2004.

While praising the city employees who have conducted the recovery efforts so far, Mr. Schumer said the military’s assistance could help finish the task.

“Simply put, there is no better outfit in the world to assist in the daunting and complex task of the recovery of human remains at ground zero, than the JPAC,” Mr. Schumer’s letter said.

Mr. Schumer said the remains of 1,151 victims have not been identified. Relatives hope that DNA testing will allow for the identification of at least some of the bone fragments.

In the months after September 11, it appeared that the search for remains would be confined to the World Trade Center site and would end when the last of the rubble had been sifted through and removed.

That is no longer the feeling among many relatives of victims. Last year, a group of them filed a lawsuit against the city for placing World Trade Center rubble at the Fresh Kills landfill on Staten Island, where they say human remains now lie beside garbage.

Still, the scope of the renewed search many relatives now demand is not clear. “How wide do you go?” asked Alexander Santora, whose son, a firefighter, died on September 11. “I have no idea. If you go as far as the dust cloud did, you’re talking about the river on both ends and 14th Street on the north. It boggles the mind. But at least the perimeter of the immediate buildings should be looked at,” Mr. Santora said.