Thursday in Pictures: January 21

Security forces detain a man at the scene of a bomb blast in Giza, Egypt, on Jan. 21, 2016. A bomb attack killed six people, including three police, near a road leading to the pyramids.

Democratic presidential candidate Sen. Bernie Sanders speaks during a campaign stop in Peterborough, New Hampshire.

Democratic presidential candidate Hillary Clinton puts her hands together while speaking during a rally at Simpson College in Indianola, Iowa.

An Aymara man holding a Wiphala flag is silhouetted against an early morning sky at the archeological site Tiwanaku in Bolivia as he waits for the arrival of Bolivia's President Evo Morales before an Andean ritual honoring the 10 years Morales has served as president. Morales elevated the status of the multi-colored flag that represents the people of the Andes, making it the co-official flag of Bolivia.

A statue of Russian Soviet poet Vladimir Mayakovsky is silhouetted in downtown Moscow.

A boy plays soccer as he waits on the border to cross into Greece, near Idomeni, Macedonia. Some 2,000 migrants began crossing into Macedonia in freezing temperatures as the country conditionally reopened its border with Greece after closing it temporarily. \"The border crossing for migrants near (Macedonian border town) Gevgelija opened early this morning, but only those migrants whose Greek registration papers show their final destination as Germany or Austria can enter,\" a senior police official in Skopje told AFP.

Pope Francis kisses a baby during an audience at the Paul VI Hall at the Vatican.

A Communist Party supporter carries a portrait of Soviet founder Vladimir Lenin as she takes part in a ceremony in Moscow's Red Square to mark the 92nd anniversary of his death.

A girl looks on during a protest by women in front of United Nations office in the Yemeni capital Sanaa against the ongoing military operations and air strikes in their country carried out by a Saudi-led coalition.