Others landed at an undisclosed location late Wednesday in "southwest Asia", the Air Force said.
On Sunday, the White House announced it would send the USS Abraham Lincoln aircraft carrier strike group and the bombers to counter Tehran.
The US Air Force released images of B-52 Stratofortress bombers landing in Qatar.
L'armée française libère quatre otages — Burkina Faso
Les deux touristes français avaient disparu le 1er mai, alors qu'ils étaient en vacances dans le parc de la Pendjari, au Bénin . Au cours de l'opération deux soldats français ont perdu la vie selon un communiqué de la présidence française.
The Trump administration has not offered specific details of the threat allegedly presented by Iran that prompted the U.S.to dispatch the aircraft carrier and B-52 bombers to the Mideast.
The US bomber strike force ordered to the Middle East by the White House to counter threats from Iran has started to arrive at America's main air base in the region.
Tensions between Washington and Tehran have escalated since Mr Trump pulled the U.S. out of the 2015 nuclear deal a year ago and re-imposed sanctions on Iranian oil exports and other sources of revenue. They were provided by the 20th Bomb Squadron of Barksdale Air Force Base in Louisiana.
"C’était l’opportunité de ma vie": l’aveu de Luiz Gustavo
Le président et le propriétaire vont décider qui va rester, quel est le projet du club, les objectifs concrets de ce club. Sous contrat jusqu'en juin 2021 à l'Olympique de Marseille , Luiz Gustavo s'interrogerait sur son avenir.
Iranian President Hassan Rouhani on Wednesday gave European leaders a 60-day deadline to find a way to shield Iran from USA sanctions targeting its economy and oil industry.
The following day, the European Union urged Iran to respect the global agreement curbing the Islamic Republic's nuclear ambitions, and added that the bloc aims to continue trading with the country despite USA sanctions. The Abraham Lincoln crossed the Suez Canal on its way to the Arabian Gulf waters on Thursday. But so far, the European Union and its member nations have not offered any new plans.
A top commander in Iran's powerful Revolutionary Guard said Friday that Tehran will not talk with the United States, an Iranian news agency reported - a day after President Donald Trump said he'd like Iranian leaders to "call me".
Google Pixel 3a hands on
Pricing on the Pixel 3a line is more than reasonable, with the Pixel 3a starting at $399 and the Pixel 3a XL starting at $479. Once a security update is available, Google says it will push the update to all devices that support this mechanism.
There was no immediate reaction from Iran, which in the past has said it turned down Trump's requests for meetings.