WASHINGTON >> Even though the bulk collection of Americans’ telephone records has ended, calls and emails are still being swept up by U.S. surveillance work targeting foreigners. Congress is making a renewed push to find out how many.

Six Republicans and eight Democrats on the House Judiciary Committee have asked the nation’s top intelligence official for the number of Americans’ emails and phone calls collected under programs authorized by Section 702 of the Foreign Intelligence Surveillance Act.

The programs target foreigners, but domestic communications sometimes are vacuumed up as well. They were first revealed to the public by Edward Snowden, who leaked files from the National Security Agency.

“Surely the American public is entitled to some idea of how many of our communications are swept up by these programs,” the committee members wrote in their April 22 letter to Director of National Intelligence James Clapper.

They weren’t the first to request the information.

In the past five years, Democratic Sens. Ron Wyden of Oregon and Mark Udall of New Mexico have asked repeatedly. Last October, a coalition of more than 30 civil liberties groups wrote Clapper seeking the information. Unsatisfied with the answer they received, they wrote him again in January.

Intelligence officials have tried to assuage concerns of Congress and others by saying that any domestic communications collected are “incidental” to the targeting of foreigners. They say Section 702 allows the government to target only non-U.S. persons reasonably believed to be located outside the United States. They say the law explicitly bars the government from targeting a foreigner to acquire the communications of an American or someone in the U.S. But they say intelligence agencies are authorized under Section 702 to query communications made with U.S. persons under certain cases with certain approvals.

Late last month, Clapper said intelligence agencies are looking into several options for providing an estimate and will do their best to come up with a number.

“This tool is a terrific producer of critical intelligence for this country and our allies,” Clapper said recently about continued need for Section 702 programs.

He did not say how soon an estimate could be released and cautioned that “any methodology we come up with will not be completely satisfactory to all parties.”

Even Congress acknowledges that producing an estimate could require reviewing actual emails, for instance, acquired under Section 702, which itself could raise privacy concerns. But lawmakers say they are only advocating a “one-time, limited sampling” of communications.

Intelligence officials held briefings last week for congressional aides to explain ways an estimate could be provided. That is something Congress wants to get before it starts debating whether to reauthorize Section 702, which is set to expire at the end of next year. The Senate Judiciary Committee plans a hearing Tuesday on the issue.

Intelligence officials also briefed privacy advocates in March and are expected to hold another this month on the best way to estimate the extent to which domestic communications are ensnared in the quest for foreign intelligence. Among the problems is determining the citizenship of a caller or emailer, or whether the person is inside or outside the United States.

“We can’t go into what I hope will be an extensive public debate without this basic information,” said Elizabeth Goitein, co-director of the Brennan Center for Justice’s program on liberty and national security.

In a recent article, Goitein wrote: “The National Security Agency acquires more than 250 million Internet communications each year under this program. Given the ubiquity of international communication, this number is virtually certain to include tens of millions of exchanges that involve Americans, but there is no official public data on how many Americans’ communications are swept up.”

Congress and privacy advocates got a glimpse into Section 702 surveillance from a congressionally mandated report that Clapper’s office released this past week. The report said Section 702 surveillance targeted 94,368 foreign persons, groups or entities outside the U.S. last year, up slightly from 92,707 in 2014.

While the year-to-year increase is small, Jameel Jaffer, deputy legal director at the American Civil Liberties Union, notes that the number of targets has risen to more than 94,000 since the surveillance became legal in 2008.

The report also said that 23,800 queries concerning U.S. persons were conducted on the database, although the report notes that one of the intelligence agencies involved in the queries, which was not identified, did not provide this information.

The report also said 4,672 search terms concerning U.S. persons were used to retrieve information from Section 702 data, but privacy experts point out that the number excludes queries conducted by the FBI.

“It’s true that the targets are foreigners, but in the course of targeting those 94,000 people, the government collects the communications of many, many — we don’t know the number — Americans,” Jaffer said. “That number is missing.”