1 / 24A large blast in the Lebanese capital, Beirut, has killed at least 70 people and injured more than 4,000. 2 / 24Videos show smoke billowing from a fire, then a mushroom cloud following the blast at the city's port.3 / 24Officials are blaming highly explosive materials stored in a warehouse for six years.4 / 24President Michel Aoun tweeted it was 'unacceptable' that 2,750 tonnes of ammonium nitrate was stored unsafely.5 / 24An investigation is under way to find the exact trigger for the explosion. Lebanon's Supreme Defence Council said those responsible would face the 'maximum punishment' possible.6 / 24Hospitals are said to be overwhelmed and many buildings have been destroyed.7 / 24President Aoun declared a three-day mourning period, and said the government would release 100 billion lira (£50.5m; $66m) of emergency funds.8 / 24A BBC journalist at the scene reported dead bodies and severe damage, enough to put the port of Beirut out of action.9 / 24The streets were chaotic in the moments after the explosion.10 / 24Prime Minister Hassan Diab called it a catastrophe and said those responsible must be held to account.11 / 24He spoke of a 'dangerous warehouse' which had been there since 2014, but said he would not pre-empt the investigation.12 / 24Local media showed people trapped beneath rubble. A witness described the first explosion as deafening, and video footage showed wrecked cars and blast-damaged buildings.13 / 24'All the buildings around here have collapsed. I'm walking through glass and debris everywhere, in the dark,' one witness near the port told AFP news agency.14 / 24The blast was heard 240km (150 miles) away on the island of Cyprus in the eastern Mediterranean.15 / 24The explosion comes at a sensitive time for Lebanon, with an economic crisis reigniting old divisions. Tensions are also high ahead of Friday's verdict in a trial over the killing of ex-Prime Minister Rafik Hariri in 2005.16 / 24Lebanon's prime minister also called for international help: 'I make an urgent appeal to friendly and brotherly countries... to stand by Lebanon and to help us heal our deep wounds,' Hassan Diab said.17 / 24UK Prime Minister Boris Johnson tweeted: 'The pictures and videos from Beirut tonight are shocking. All of my thoughts and prayers are with those caught up in this terrible incident.18 / 24US President Donald Trump sent his deepest sympathies after what he called 'a terrible attack', and his Secretary of State Mike Pompeo offered assistance, tweeting: 'We are monitoring and stand ready to assist the people of Lebanon as they recover from this horrible tragedy.'19 / 24France said it was sending aid and resources to Lebanon.20 / 24Iran would 'render assistance in any way necessary' Foreign Minister Mohammad Javad Zarif tweeted, while Saudi Arabia expressed its full solidarity with Lebanon.21 / 24Israel said in a statement that it had 'approached Lebanon through international security and diplomatic channels and has offered the Lebanese government medical and humanitarian assistance'.22 / 24The German foreign ministry said the blast had been felt at its embassy in the city.23 / 24'We cannot for the moment exclude German nationals figuring among the dead and wounded,' it said in a statement. Meanwhile, on Twitter Pray for Beirut was trending.24 / 24Shocking images from Beirut blast the blast have gone viral on social media