WASHINGTON (AP) — The government's authority to intercept electronic communications of foreigners — both spies and terrorist targets — will expire at year's end unless the Senate extends a law that is under challenge from a bipartisan group of senators.

In a case in which national security bumps up against privacy, more than a dozen senators say they're concerned that conversations and emails of Americans are swept up in the monitoring. Americans, they contend, can then become targets of surveillance without the protection of a court warrant.

Senate Majority Leader Harry Reid struggled Thursday to get the five-year extension of the Foreign Intelligence Surveillance Act before the Senate, but those questioning the law blocked any action until they could get votes on their proposals to modify the bill.

The Obama administration strongly defended the law, saying in a statement that it has been "invaluable to the U.S. government's efforts to detect and prevent threats to America and its allies, while providing robust protections for the civil liberties and privacy of U.S. persons."

The statement added: "Failure to reauthorize the (law) would result in a significant loss of intelligence and impede the ability of the intelligence community to respond quickly to new threats and intelligence opportunities."

The House in September approved a five-year extension of the law by a vote of 301-118.

Sen. Ron Wyden, a liberal Democrat from Oregon, led the effort to block consideration of the bill unless it's amended. Along with a dozen colleagues, including conservative Republicans, Wyden demanded votes on amendments that would:

—Require the director of national intelligence to report publicly findings on the privacy impact of the surveillance law. Specifically, the report would include estimates, if they exist, of the number of U.S. communications collected under the law.

—Fix what the senators call a loophole that allows the government to search the communications collected, in a deliberate attempt to find phone calls and emails of specific Americans without a warrant or emergency authorization. Continued...