India, Oct. 22 -- Indian stock markets opened lower on Thursday as rising oil prices, elevated US Treasury yields and weakness across Asian markets prompted investors to turn cautious. The decline pushed the Nifty below the 22,700 mark, with auto, metal and healthcare shares among the biggest early losers.

The Sensex dropped 366.36 points, or 0.50%, to open at 73,343.33. The Nifty 50 began trading at 22,687.75, down 123.60 points, or 0.54%.

Why are Sensex and Nifty falling today?

Elevated crude oil prices and high US bond yields remained key concerns for investors. Rising oil prices can increase India's import bill and add to inflationary pressures, while higher US yields can make emerging-market assets less attractive.

Weakness in As...