Protests have erupted across U.S. cities and beyond over the killing of African-American George Floyd, who died after a police officer knelt on his neck in Minneapolis on May 25.

Derek Chauvin, a now-fired police officer, was seen in the amateur video footage pressing his knee on the neck of the unarmed male African-American for several minutes although the latter had been arrested, handcuffed and pinned to the ground. The 46-year-old Floyd later died. Chauvin and three other officers involved in the incident have been sacked.

After nine days of widespread protests, U.S. prosecutors on Wednesday upgraded the charge against Derek Chauvin to second-degree murder, and also charged the three other former officers with aiding and abetting murder.

Here's what we know so far:

- Protests are unfolding across U.S. cities for the 11th consecutive night. Demonstrations are also staged in many other major cities around the world.

- Minneapolis city has agreed to ban the use of chokeholds by police as a way of restraining suspects during arrest.

- Washington D.C. Mayor Muriel Bowser has named a plaza "Black Lives Matter" with a massive two-block long mural painted onto a street leading up to the White House.

- Chauvin is scheduled to appear in court for a hearing at 1:30 p.m. CT on June 8. A judge on Thursday set bail for the three other former officers, J. Alexander Keung, Thomas Lane and Tou Thao, at one million U.S. dollars each, or 750,000 U.S. dollars under certain conditions.

- Floyd's death was due to cardiopulmonary arrest – the stopping of the heart – the final autopsy results released by the Hennepin County Medical Examiner said, adding that he had tested positive for COVID-19 although there is no indication that it was a factor in his death.