The State Department says U.S. diplomatic posts in 19 cities in the Muslim world will be closed through Saturday "out of an abundance of caution."

State Department spokeswoman Jen Psaki says the decision to keep the embassies and consulates closed is "not an indication of a new threat."

Diplomatic facilities will remain closed in Egypt, Jordan, Libya, Saudi Arabia and Kuwait, among other countries.

The Obama administration announced Friday that the posts would be closed over the weekend and the State Department announced a global travel alert, warning that al-Qaida or its allies might target either U.S. government or private American interests.

The top Republican on the Senate Intelligence Committee calls it the "most serious threat I've seen in a number of years."

Terror threat: Senator Cites Increased 'Chatter'

U.S. State Department in Washington DC (Alex Wong/Getty Images)

Sen. Saxby Chambliss of Georgia is describing "the chatter" detected by U.S. intelligence agencies that led the Obama administration to order the weekend closure of 21 U.S. embassies and consulates in the Muslim world, and issue a global travel warning to Americans.

Chambliss tells NBC's "Meet the Press" that "there's an awful lot of chatter out there" and he says it's "very reminiscent of what we saw pre-9/11." He says it's critical that "we do the right kind of planning."

The top Democrat on the House intelligence committee says the decision to issue a global terror alert was based on intercepted communications from "high-level people in al-Qaida in the Arabian Peninsula." The Maryland congressman, Dutch Ruppersberger, told ABC's "This Week" that the talk was about a "major attack." He didn't provide details of the threat.