Two enormous explosions devastated Beirut's port on Tuesday, leaving at least 100 people dead and thousands injured, shaking distant buildings and spreading panic and chaos across the Lebanese capital.The second blast sent an enormous orange fireball into the sky, immediately followed by a tornado-like shockwave that flattened the port and swept the city, shattering windows kilometres (miles) away.Prime Minister Hassan Diab said that 2,750 tonnes of the agricultural fertiliser ammonium nitrate that had been stored for years in a portside warehouse had blown up, sparking "a disaster in every sense of the word".Bloodied and dazed wounded people stumbled among the debris, glass shards and burning buildings in central Beirut.The Lebanese Red Cross put the death toll at 100 with over 4,000 injured Wednesday morning."What happened today will not pass without accountability," said Diab. "Those responsible for this catastrophe will pay the price."General Security chief Abbas Ibrahim earlier said the "highly explosive material" had been confiscated years earlier and stored in the warehouse, just minutes walk from Beirut's shopping and nightlife districts.The blasts were so massive they shook the entire city and could be heard throughout the small country, and as far away as Nicosia on the eastern Mediterranean island of Cyprus, 240 kilometres (150 miles) away.A soldier at the port, where relatives of the missing scrambled for news of their loved ones, told AFP: "It's a catastrophe inside. There are corpses on the ground. Ambulances are still lifting the dead.""It was like an atomic bomb," said Makrouhie Yerganian, a retired schoolteacher in her mid-70s who has lived near the port for decades."I've experienced everything, but nothing like this before," even during the country's 1975-1990 civil war, she said."All the buildings around here have collapsed."Her 91-year-old uncle, who lived in the same building, was wounded in the blast and later died.AFP correspondents across the city saw shop and apartment windows blown out and streets covered with broken glass.Photos posted online even showed damage to the inside of Beirut airport's terminal, some nine kilometres from the explosion.Hospitals already struggling with the country's coronavirus outbreak were overwhelmed by the influx of wounded people and the country's Red Cross called for urgent blood donations.As the national defence council declared Beirut a disaster zone, Diab appealed to Lebanon's allies to "stand by" the country and "help us treat these deep wounds".Condolences poured in from across the world with Gulf nations, the United States and even Lebanon's arch foe Israel offering to send aid.AFP video footage showed areas of near-complete devastation, with cars flipped onto their roofs like children's toys, warehouses flattened and survivors drenched from head to toe in their own blood."We heard an explosion, then we saw the mushroom," said a Beirut resident who witnessed the second deafening explosion from her balcony in the city's Mansourieh district."The force of the blast threw us backwards into the apartment."An AFP correspondent at the scene minutes after said every shop in the Hamra commercial district had sustained damage, with entire storefronts destroyed and many cars wrecked.A huge blaze sent up black smoke from the port area, as helicopters dumped water on burning buildings.A ship moored off the port was on fire, and the blasts also damaged a vessel deployed with United Nations peacekeeping force UNIFIL and injured some of its personnel.Hundreds immediately shared their shock and grief on social media."Buildings are shaking," tweeted one resident, while another wrote: "An enormous, deafening explosion just engulfed Beirut. Heard it from miles away."Online footage from a Lebanese newspaper office showed blown out windows, scattered furniture and demolished interior panelling.The explosions hit a country already reeling from its worst economic crisis in decades which has left nearly half of the population in poverty, as well as from the coronavirus pandemic.Lebanon's economy has collapsed in recent months, with the local currency plummeting, businesses closing en masse and poverty soaring at the same alarming rate as unemployment.Charity Save the Children said "the incident could not have occurred at a worse time".The explosions came three days before a UN tribunal's verdict on the murder of former Lebanese premier Rafic Hariri, who was killed in a huge 2005 truck bomb attack.Four alleged members of the Shiite Muslim movement Hezbollah are on trial in absentia at the court in the Netherlands over the huge Beirut bombing that killed Sunni billionaire Hariri and 21 other people.A woman in the city centre Tuesday told AFP the blast "felt like an earthquake" and "bigger than the explosion in the assassination of Rafic Hariri in 2005".