Hello. Germans are searching for answers in the aftermath of an attack against a Christmas market in Magdeburg in which five people were killed, including a nine-year-old boy. Frank Gardner looks at the possible missed opportunities and security failures. A BBC investigation reveals how China cracked down on protests in Tibet over a dam. Plus, take a look at the restoration of Italy's largest medieval mosaics, and find out about an unconventional and festive-themed drug raid in Peru.

TOP OF THE AGENDA

Security under scrutiny after fatal attack

A gap in the barriers surrounding the Christmas market was large enough to allow emergency vehicles to pass through. Credit: EPA

German authorities are facing questions about security at the Christmas market where a car was driven into a crowd on Friday, killing five people and injuring more than 200. The suspect, who was arrested at the scene, has been named as Saudi citizen Taleb al-Abdulmohsen. Saudi authorities said they warned their German counterparts about him, writes security correspondent Frank Gardner. Frank says there is "no question" that German authorities "have made some serious errors of omission" when it comes to the case of al-Abdulmohsen, as well as the failure to close off or guard the emergency access route to the Christmas market that allowed him to allegedly drive his BMW into the crowds.

• Tributes to victims: Nine-year-old André Gleissner was the youngest of five people who were killed in the attack.

• Eyewitness account: A woman who was at the Christmas market has told local media she had her boyfriend in her arms when the car used in the attack came speeding towards them.

• At the scene: Correspondent Bethany Bell speaks to people in Magdeburg saddened and angered by the attack.

WORLD HEADLINES

BEYOND THE HEADLINES

China cracks down on rare Tibet protests

Beijing's plan to build another dam on the Jinsha river, which runs through Tibetan territories, led to protests. Credit: Getty Images

Hundreds of Tibetans protesting against a Chinese dam were rounded up in a harsh crackdown earlier this year, the BBC has learnt from sources and verified footage. In response to our queries, the Chinese embassy in the UK did not confirm nor deny the protests or the ensuing crackdown.

And finally...

An undercover police officer wearing a Grinch costume has carried out a drug raid in Lima, Peru. Video distributed by the national police agency, which is renowned for using costume-clad agents, shows officers smashing a door open before entering a house. Take a look.