The U.S. Federal Energy Regulatory Commission (FERC) said on Thursday it referred two matters from the February freeze in Texas to its investigations division to look for possible market manipulation or other violations. FERC said its analytics and surveillance division has been examining wholesale natural gas and electricity market activity during the February freeze, also known as winter storm Uri, to determine if any market participants engaged in market manipulation or other violations. The analytics group analyzed gas and power market and trade data, evaluated hotline tips and met with numerous interested parties. Those examinations led to 14 inquiries into gas and electricity market participant behavior, resulting in the two matters referred for investigation. FERC said its examination remains ongoing and additional matters may be referred for investigation. The freeze left more than 4.5 million people in Texas without power - some for as long as four days - and killed more than 100 people. read more During the winter storm, the Electric Reliability Council of Texas (ERCOT), which operates most of the power grid in Texas, ordered rolling blackouts to prevent the grid from collapsing as extreme cold shut numerous power plants and froze gas pipelines. In addition, power and gas prices soared to record highs in several parts of Texas and other U.S. Central states during the storm, costing utilities and their consumers billions of dollars that will have to be paid back over years.