Massive explosion rips through Lebanese capital Beirut

A massive explosion has torn through the Lebanese capital Beirut causing. Dozens of people are known to have been killed in the blast with many more unaccounted for — officials say they expect the death toll to rise sharply. Many thousands of people have been injured. It's not yet known what caused the explosion. Lebanon's prime minister says his country is facing a catastrophe and Beirut is in mourning. He vowed to hold to account whoever was responsible — although its not yet clear whether the explosion was deliberate. The huge blast in the city’s port sent shockwaves across the city, destroying many buildings and blowing out windows many miles away. Hospitals in the city were overwhelmed by thousands of injured people seeking treatment. Sophie Raworth presents BBC News at Ten reporting by Middle East Editor Jeremy Bowen.