"Today I went to the market at about noon, and it seemed pretty calm," he said, adding that he didn't fear for his safety. "Most of the kidnappings of the Western NGO types -- that happens at the other end of the city. You have a sense of where not to go."

Meanwhile, many Yemenis have expressed anger over a series of U.S. drone strikes that have been authorized in the country over the past 10 days, the first such attacks in seven weeks.

.@basheerMoh We will see if this is how you feel when your family dies "By mistake" when the drone strikes :) -- Sarah Jamal (@Sarah_Sanaa) August 7, 2013

2 #Drones strikes in 24h 1 in Marib 1 in Shabwa, the Total is 5 #Drone strikes in 2 weeks... Happy Eid from Drones 2 #Yemenis #Yemen #Shame -- Marwa Baabbad (@mabaabbad) August 7, 2013

Hakim Almasmari, a Michigan native who publishes the Yemen Post newspaper, said he had noticed that more people were staying indoors, and he, like the BBC's Yemen correspondent, said the mood in Sanaa was "tense."

He said he had also overheard outrage that U.S. drone strikes occurred during Ramadan, saying "the timing is very sensitive." There have been 16 drone strikes in Yemen this year.

Part of the issue now, though, is that the U.S. has dispatched a large surveillance plane to monitor the area -- bringing with it a loud buzzing sound and rattling windows. Some Yemenis are mistaking it for drone aircraft, news reports have said.

"Drone or normal plane, the fear was expressed by many," Haykal Bafana, a Yemeni attorney, told GlobalPost. "Many thought it was a drone about to attack, and it made them scared."

What's more, some Yemeni officials have expressed disappointment that the U.S. would take such aggressive measures there, saying the actions imply that Washington doesn't trust Yemen to handle its own security threats. Yemeni officials said on Wednesday they foiled an Al-Qaeda plan to capture a major port in the country, but it's unclear whether that plot was the threat that prompted the embassy closings.

Meanwhile, the opinion of civilians toward the U.S. seems to be more mixed. Coombs said that while some graffiti around his neighborhood reads, "Death to America," he hasn't experienced any anti-Americanism around town. A cab driver recently gave a "thumbs up" to the news that a drone strike killed alleged militants, adding "I hate Al Qaeda," he said.

Much of the anti-American sentiment, he said, simmers online among the country's youthful, plugged-in community. In his experience, Yemenis seem to direct their resentment toward U.S. officials, but not its citizens.

"When I go out, [anti-Americanism] doesn't come up," he said. "Things like inflation are more important. Buying food is getting more difficult."