Attorney General Eric Holder said during a Senate Appropriations Committee hearing Thursday that a surprising number of people use the U.S. Postal Service to ship illegal drugs.

“The postal service, the mails are being used to facilitate drug dealing,” Holder said. “It is shocking to see the amount of drugs that get pumped into communities all around this country through our mail system, and we have to deal with that.”

The nation’s top law-enforcement official was responding to questions from Sen. Lisa Murkowski, R-Alaska, who said remote communities in her state were flush with drugs, including heroin and synthetic substances.

“We’re seeing some really devastating impact in our very, very remote communities where the only way to get these drugs in is by the mail, and the drugs are coming into the community through the mails,” Murkowski said.

“Through the post office?” interrupted a surprised Sen. Barbara Mikulski, D-Md.

“Through the United States post office, madam chairman,” a piqued Murkowski replied. “We need to get on it yesterday.”

The U.S. Postal Inspection Service frequently catches people mailing drugs and made 1,760 arrests in fiscal year 2012, The Advocate, a Louisiana newspaper, reported – up 33 percent from the previous year. Press representatives for the service, which is not directly supervised by Holder, did not immediately respond to a request for comment.

Perhaps surprisingly, senators did not grill Holder about marijuana enforcement matters. Holder announced in August he would not seek to block the opening of recreational pot stores in Colorado and Washington – although the drug remains illegal under federal law. Other states may legalize the drug in the near future.

Heroin, however, was among the most-discussed topics. Lawmakers peppered the attorney general with anecdotes and recommendations. Sens. Jeanne Shaheen, D-N.H., Patrick Leahy, D-Vt., Murkowski and Mikulski all expressed concern about increased use of heroin among constituents.

Mikulski said heroin is “selling in Baltimore today for $6 a bag, cheaper than buying a bag of kale” and complained that suburban drug tourists were visiting the inner city “looking into heroin markets that were featured in some of those awful movies about us.”

Holder, who was before the committee to discuss his department's 2015 budget request, agreed to lead multiagency discussions on the apparent boom in heroin use, but stressed he favors a public health emphasis.