Investors also awaited minutes of the Fed's June meeting to gauge how committed it was to hiking rates this year.
North Korea said it had conducted a test of a newly developed intercontinental ballistic missile that can carry a large and heavy nuclear warhead. South Korean and US troops fired missiles into the waters off South Korea to show their deep strike precision capability.
At 11:35 am, the S&P BSE Sensex was trading at 31,235, up 25 points, while the broader Nifty50 was ruling at 9,627, up 13 points.
In the broader market, the S&P BSE Midcap and S&P BSE Smallcap index gained 0.6% and 0.8% respectively.
"The internal trendline that pierces through 9,640, also discussed yesterday, shall continue to be a challenge, and to this end, dips to 9,580 should be a convenient entry. And until then, volatility should be the order of the day. Alternatively, direct rise above 9,650 could see some short covering, but a directional upside is less favoured," said Geojit Financial Services in a note.
Buzzing Stocks
M&M, Reliance, Sun Pharma and Tata Steel gained the most on BSE Sensex while Bharti Airtel, Wipro, HDFC and Infosys lost the most on the index.
Mahindra & Mahindra gained 2.5% after it reduced prices of its utility vehicles and SUVs by up to 6.9% on an average to pass on the GST benefit to customers.
Ultratech Cement advanced 0.7% after it cut cement prices by up to 3%.
Infosys lost 0.7% after media reports that hikes have been only in the range of 5-11% and it would be put into effect from July 1.
Shares of Texmaco Rail, an Adventz Group firm, jumped over 11% intra-day after the group signed a $2-billion-plus agreement with Israel's Lesico Group to collaborate in light rail transit (LRT) projects in Tel Aviv and Jerusalem.
Global Markets
Asian share markets got off to a subdued start on Wednesday as simmering tensions on the Korean peninsula supported safe-harbors including the yen and gold.
MSCI's broadest index of Asia-Pacific shares outside Japan was off 0.01%, having shed 0.6 %on Tuesday when North Korea fired a missile into Japanese waters.
Japan's Nikkei eased 0.1%, as did South Korea's main index.
A holiday in the United States and a dearth of major data kept activity muted across Asia, though minutes of the Federal Reserve's last meeting due later in the day could provide some impetus.