Smoke from fires caused by multiple gas tank explosions rises against the skyline in Dallas, Texas July 25, 2007.(Xinhua/Reuters Photo)

    WASHINGTON, July 25 (Xinhua) -- At least two people were seriously injured on Wednesday in a series of large explosions that rocked an area near downtown Dallas, in the southwestern U.S. state of Texas, on Wednesday, CNN reported.

    The blasts were apparently caused by gas tanks used for welding, showering flaming shrapnel around the area, the television reported.

    A preliminary investigation found that the explosions at the Southwest Industrial Gases, Inc. facility might be caused by a truck loaded with oxygen canisters.

    The truck might have exploded at the facility, causing gas tanks there to explode.

    Residents within half a mile (0.8 kilometer) of the site of explosions were evacuated, and part of the I-35 and I-30 highways close to the site that sells liquefied natural gas was closed.

    The Environmental Protection Agency has sent emergency responders to the scene, to monitor air quality after the explosions, news reports said.