Mumbai, August 27 (PTI): The BSE benchmark Sensex extended its fall for second straight week by slumping 294.75 points and once again slipping below the psychological 28K, while the broader Nifty lost 94.35 points to fall below the crucial 8,600-level. Bears took control over bulls in a lopsided trading week following appointment of new RBI chief Urjit Patel which triggered wariness and set-in-motion the debate over the topic of domestic rate-cut and inflation. However, sentiments were dominated by global caution on eagerly awaited US Federal Reserve Chair Janet Yellen speech at the Kansas City Fed’s annual Monetary Policy Symposium in Jackson Hole, Wyoming, which could provide hints about the timing of the next rate hike, in view of recent set of hawkish tone from senior Fed officials.