Ten days after the Boston Marathon bombing, more than half of the Americans consider another terror attack as likely in the coming weeks, according to a Gallup poll released Friday.

Fifty-one percent of the respondents believe it is "very likely" or "somewhat likely" that there will be acts of terrorism in the U.S. over the next several weeks, up from 38 percent in August 2011, the poll shows.

Another 34 percent consider it "not too likely," while 12 percent say it is "not at all likely," according to the April 24-25 poll.

Despite Americans' elevated worry about impending terror attacks, the percentage of those worried that they themselves or a family member could become a terror victim only climbs slightly to 40 percent from 36 percent in August 2011, it discovers.

At the same time, the poll finds that Americans' confidence in U.S. government's ability to protect citizens from terrorism declines to 70 percent, from 75 percent in August 2011.

About three in 10 say they have low confidence in the government's counter-terrorism ability, including 21 percent who say they don't have much confidence and 8 percent who say have none confidence at all.

This may reflect media speculation that the U.S. government may have overlooked important intelligence as they failed to preempt the Boston bombing suspects, Tamerlan and Dzhokhar Tsarnaev, even as Russia once alerted it in 2011 that Tamerlan was a strong believer in radical Islam.

The two brothers of Chechen origin detonated two self-made bombs near the finish line of the Boston Marathon last Monday, killing three people and injuring more than 200 others. Tamerlan was killed in a shootout with the police, while Dzhokhar was detained last Friday after a massive manhunt that paralyzed the city of Boston. Endi