WASHINGTON, Oct 11 (Reuters) - A bipartisan group of

U.S. lawmakers asked AT&T ( T ), Verizon Communications ( VZ ),

and Lumen Technologies ( LUMN ) on Friday to answer questions

after a report Chinese hackers accessed the networks of U.S.

broadband providers.

The Wall Street Journal reported Saturday hackers obtained

information from systems the federal government uses for

court-authorized wiretapping, and said the three companies were

among the telecoms whose networks were breached.

House Energy and Commerce Committee Chair Cathy McMorris

Rodgers, a Republican, and the top Democrat on the committee

Representative Frank Pallone along with Representatives Bob

Latta and Doris Matsui asked the three companies to answer

questions. They are seeking a briefing and detailed answers by

next Friday.

"There is a growing concern regarding the cybersecurity

vulnerabilities embedded in U.S. telecommunications networks,"

the lawmakers said. They are asking for details on what

information was seized and when the companies learned about the

intrusion.

AT&T ( T ) and Lumen declined to comment, while Verizon did not

immediately comment.

It was unclear when the hack occurred.

Hackers might have held access for months to network

infrastructure used by the companies to cooperate with

court-authorized U.S. requests for communications data, the

Journal said. It said the hackers had also accessed other

tranches of internet traffic.

China's foreign ministry said on Sunday that it was not

aware of the attack described in the report but said the United

States had "concocted a false narrative" to "frame" China in the

past.