Tech shares endured another ugly session Monday amid worries about Washington's unsettled spending, budget debates and lackluster expectations for the upcoming earnings season, as Facebook suffered a 5.4% loss in value due to the ongoing massive outage that also affected Instagram and WhatsApp too.

The tech-rich Nasdaq Composite Index suffered the biggest losses of the major indices, ending down 2.1% at 14,255.48.

The Dow Jones Industrial Average shed 0.9% to 34,002.92, while the broad-based S&P 500 tumbled 1.3% to 4,300.46.

Facebook and its Instagram and WhatsApp platforms were down in parts of the world late Monday.

The company said it was "aware that some people are having trouble accessing Facebook app" and it was working on restoring access.

The company did not say what might be causing the outage, which began around 11:45 a.m. ET (4:45 p.m. GMT). It is normal for websites and apps to suffer outages, though one on a global scale is rare. Users reported being unable to access Facebook in California, New York and Europe.

Facebook is going through a major crisis after the whistleblower who was the source of The Wall Street Journal's series of stories exposing the company's awareness of internal research into the negative effects of its products and decisions went public on "60 Minutes" on Sunday.