Iranian president Hassan Rouhani.
The Pentagon said the threat was unverified and would be investigated.
US President Barack Obama arrives to deliver the State of the Union address.
This handout picture released by International Atomic Energy Agency (IAEA) on February 17 shows a member of the IAEA mission team inspecting TEPCO’s Fukushima Daiichi Nuclear Power Station in Okuma, Fukushima prefecture.
Mall of America said it had taken extra security measures in response to the threat by the Shebab.
A Kurdish fighter holds a position during a clash with Islamic State (IS) jihadists in the Syrian border town of Ain al-Arab.
Houthi fighters holding weapons ride on the back of a patrol truck in Sanaa.
Indonesian Armed Forces Chief Gen. Moeldoko (center left) and Chief of the National Transportation Safety Board Tatang Kurniadi (center right) look at one of the black boxes of the ill-fated AirAsia Flight 8501 that crashed in the Java Sea during a press conference at airport in Pangkalan Bun, Indonesia, on January 12.