SAN FRANCISCO (CBS SF) – San Francisco City Hall will be lit up in the colors of the Armenian flag Friday to mark the centennial of the Armenian genocide under the Ottoman Empire.

Mayor Ed Lee and members of the Bay Area Armenian community will be joined by other officials and guests for a presentation which will include a dance ensemble and photo exhibit.

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Armenians worldwide are commemorating the killings of 1.5 million people by Ottoman Turks – in massacres, deportations and forced marches – which Armenians, their supporters and many other scholars consider genocide.

Turkey denies the deaths constituted genocide, and U.S. President Barack Obama has refrained from using the term when referring to the killings. Pope Francis has called the Armenian killings “the first genocide of the 20th Century,” which prompted Turkey to recall its ambassador to the Vatican.

Earlier this month, The European Parliament also triggered Turkey’s ire by passing a non-binding resolution to commemorate “the centenary of the Armenian genocide.”

In Los Angeles, thousands were expected to march in in the city for the 100th anniversary commemoration.

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Mayor Eric Garcetti was among the expected speakers at a morning rally that will be followed by a six-mile procession from the Little Armenia neighborhood to the Turkish consulate.

Protesters will demand the U.S. government acknowledge that the deaths of their ancestors constituted genocide, a term used to describe violence intended to destroy an entire group based on ethnicity, race or religion.

“We commemorate with deep respect the Ottoman Armenians who lost their lives during the relocation in 1915 and we share in the grief of their children and grandchildren.” The Los Angeles office of the Consulate General of Turkey said in a statement Thursday. “But we are against exploiting history and the sufferings for political purposes. … The term ‘genocide’ is a legally binding, morally obstructing, historically wrong and politically misused concept that prevents the discussion of the events.”

Officially using the genocide designation could risk U.S. relations with Turkey, an important ally. Turkey withdrew its U.S. ambassador more than four years ago when a House panel approved a resolution branding the killing of Armenians as genocide. The resolution eventually stalled.

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