The two brothers suspected in the Boston Marathon bombings, who police say engaged in a gun battle with officers early Friday after a frenzied manhunt, were not licensed to own guns in the towns where they lived, authorities said on Sunday.

In the confrontation with police on the streets of a Boston suburb, Tamerlan and Dzhokhar Tsarnaev were armed with handguns, at least one rifle and several explosive devices, authorities say.

But neither brother appears to have been legally entitled to own or carry firearms where they lived, a fact that may add to the national debate over current gun laws. Last week, the U.S. Senate rejected a bill to expand background checks on gun purchases, legislation that opponents argued would do nothing to stop criminals from buying guns illegally.

Tamerlan Tsarnaev, 26, who was killed in the shootout with police, would have been required to apply for a gun license with the local police department where he lived in Cambridge, Massachusetts.

But there is no record of him having done so, according to Cambridge Police Department spokesman Dan Riviello.

Even if he had earlier received a gun license from somewhere outside Cambridge, that license would have to be registered with Cambridge police upon becoming a resident of the city, Riviello said. In Massachusetts, gun licenses are issued by municipal police departments.

"There is no record of him having a license to carry," Riviello told Reuters.

Tsarnaev's younger brother Dzhokhar, 19, who was captured alive on Friday after the manhunt, would have been too young to get a handgun license. Under state law, residents under 21 may only apply for a so-called firearms identification card, which allows the holder to own only rifles that hold 10 rounds or less and shotguns.

Dzhokhar Tsarnaev had no record of a firearms ID card in Cambridge. The police department in Dartmouth, where Dzhokhar was a student, said they had no record of gun licenses or ID cards for either brother.

Police in nearby New Bedford, where the younger brother may have lived in the past, could not confirm on Sunday whether they had issued Dzhokhar Tsarnaev a firearms ID card.

Federal law enforcement agencies have not confirmed a full tally of the brothers' arsenal.

Within hours of their images being released on Thursday, the two brothers are accused of shooting dead a Massachusetts Institute of Technology campus police officer in his car, hijacking at least one car at gunpoint, and of shooting at least one police officer during the gun battle in nearby Watertown.