Mumbai, Jan 7 (IANS): Key Indian equity indices came under fresh a bout of pressures on Thursday due mainly to geopolitical developments such as the hydrogen bomb test by North Korea and tensions in West Asia, as also weak signals from the US and Chinese economies.

As a result, the 30-share sensitive index (Sensex) of the Bombay Stock Exchange (BSE) fell below the psychologically-important 25,000-point mark intra-day and was ruling at 25,035.81 points with a loss of 370.52 points or 1.46 percent over the previous close at 25,406.33 points.

At the National Stock Exchange, the broader 50-share Nifty was quoting at 7,624.00 points, with a loss of 117.00 points, or 1.51 percent. On Wednesday, while the Sensex had ended with a loss of 174.01 points, or 0.68 percent, the Nifty shed 43.65 points, or 0.56 percent.

Only four out of the 30 Sensex shares were trading in the positive territory on Thursday morning.

"The US stocks declined in early session and ended the day in the negative, owing to geopolitical concerns -- tensions between Saudi Arabia-Iran and possible nuclear test in North Korea -- and fears over current state of the Chinese economy," Angel Broking said ahead of the opening bell.

"European markets also declined yesterday, hit by weakness in the commodity sector as concerns over the Chinese economy resurfaced after it allowed the yuan to weaken further. Geopolitical concerns also weighed on the market," it added.