Some examples of this are shown below, but I'm sure there have been other similar cases.
The plane was still smoldering on the ground when government officials began making extraordinary pronouncements that there was "no connection to terrorism" and it was just an "unfortunate accident." I could go on at length about this case... More examples of suppressed news stories can be found here and here.
More examples of pro-Islam bias in the media can be found here.
The Islamic terrorist attack in San Bernardino, California is discussed on its own page.
Overviews Leaked FBI documents show that more than 7,000 'terrorist encounters' occurred within the US in a year.