The San Francisco Police Department is on heightened alert Sunday night because of what U.S. officials call a serious and specific al-Qaida threat.
There is no direct threat to San Francisco, but police have been monitoring various areas around the city and will deploy more resources if needed, police Officer Gordon Shyy said today.
"I want to remind citizens if they see something, say something," Shyy said. "We want to be proactive given the State Department's warnings in order to protect our citizens and infrastructure in San Francisco."
The Associated Press also reported today that 19 embassies and consulates closed Sunday in response to a security alert would remain closed through Saturday.
Travelers and U.S. citizens living abroad were first warned Friday that terrorist attacks are being planned this month against U.S. and Western targets, particularly in the Middle East and North Africa.
"Current information suggests that al-Qaida and affiliated organizations continue to plan terrorist attacks both in the region and beyond, and that they may focus efforts to conduct attacks in the period between now and the end of August," U.S. State Department officials said in an advisory.
U.S. citizens were especially warned to remain aware of the potential for attacks on public transportation systems and other tourist infrastructure.
Travelers should stay aware of their surroundings and adopt appropriate safety precautions.
In particular, travelers should register their travel plans with the consular section of the U.S. Embassy through the State Department's travel registration website and enroll in the Smart Traveler Enrollment Program, either online or at the nearest embassy or consulate.
The program provides travelers with security updates and makes it easier for the nearest U.S. embassy or consulate to contact them in an emergency.