HONG KONG, Aug. 6 — Pro-Beijing lawmakers approved legislation here today giving broad authority to the police to conduct covert surveillance, including wiretapping phones, bugging homes and offices and monitoring e-mail.

The bill passed the 60-member Legislative Council on a vote of 32 to 0 soon after pro-democracy lawmakers walked out of the chamber in protest early this morning. The Democratic Party and its allies had tried to introduce nearly 200 amendments to the bill through four days of marathon debates, but all were defeated or ruled out of order.

Ambrose S.K. Lee, the secretary for security, welcomed the legislation, saying it was necessary to fight crime. “I wish to assure the residents of Hong Kong that the law now is a good balance between effective law enforcement on the one hand and the protection of privacy on the other,” he said.