NASDAQ halts stock trading amidst data glitch (Updated)

The NASDAQ, which serves as the primary exchange for trading tech stocks, has taken the unusual step of suspending trades in response to a data glitch. [Update: NASDAQ says trading will resume at 3:25ET]
The halt began on a stock-by-stock basis at 12:18pm ET and resulted in the NASDAQ’s usual up-and-down graph displaying a flat line:
Nasdaq screenshot
According to the Wall Street Journal, the exchange began sending notices that trading for individual securities was being suspended. The notices were sent in alphabetical order and, according to the Journal, noted that:

The issue stemmed from a data feed that provides market data for Nasdaq-listed securities

The Journal also reports that the the New York Stock Exchange has halted trades in NASDAQ-listed securities and has cancelled orders in those stocks. The NASDAQ glitch is likely to distort Wednesday’s calculation for other stock barometers such as the Dow Jones Industrial Average.
NASDAQ officials have so far declined to comment.
Update 2: Bloomberg reports that Nasdaq will let stand all trades executed from 12:14:03 to 12:23:31.