Mumbai, Aug 29 (PTI): The BSE Sensex plunged by over 362 points to close at one-week low of 31,388.39 while NSE Nifty ended below 9,800 mark due to selling by investors rattled by North Korea's launch of a missile over Japan.

The August month expiry in the derivatives segment on Thursday also hit sentiment.
Most of the Asian markets ended lower and European shares opened in the red as geopolitical tensions escalated after North Korea fired a ballistic missile over northern Japan, brokers said.

The 30-share Sensex declined by 362.43 points or 1.14 per cent to 31,388.39, its lowest closing since August 22 when it closed at 31,291.85. The Sensex also recorded its biggest single day fall since July 18 when it had lost 363.79 points.

The gauge had gained 491.97 points in the previous four sessions.
The wider NSE Nifty slipped below the 9,800-mark and hit a low of 9,783.75 before settling down by 116.75 points or 1.18 per cent at 9,796.05.

Power producer NTPC emerged as the biggest loser among Sensex constituents by plunging 2.80 per cent to Rs 168.50 after the government said it would sell 5 per cent stake in the country's largest power producer at Rs 168 to raise about Rs 7,000 through a two-day share sale.

HDFC, HDFC Bank, Reliance Industries and Infosys also fell up to 2.20 per cent, dragging the indices deep into the red.