For months, foreign companies in China have been quietly enduring increased scrutiny from Chinese government antitrust enforcers, issuing only occasional terse statements as they have been increasingly targeted by surprise raids on their offices, protracted investigations of their operations and escalating fines. Now, tentatively but together, they appear to be pushing back. On Wednesday, the U.S.-China Business Council, a group that lobbies on behalf of about 220 large American companies with operations in China, issued a report taking direct aim at China’s recent enthusiastic application of its six-year-old antimonopoly law and highlighting a litany of ways that it says enforcement could be improved. “For American businesses operating in China, China’s A.M.L. regime is creating more questions than answers,” John Frisbie, the president of the Washington-based council, said in a news release, referring to the antimonopoly law. “Will China use the A.M.L. to protect its domestic industry rather than promote fair competition? Is the Chinese government using the A.M.L. to force lower prices, rather than letting the ‘market play the decisive role’ as enshrined in China’s new economic reform program?”