Iraqi pro-government forces fire an anti-tank cannon near al-Sejar village, north-east of Fallujah, on May 25, 2016, as they take part in a major assault to retake the city from the Islamic State (IS) group. Iraqi forces, consisting of special forces, soldiers, police, paramilitary-fighters and pro-government tribesmen, launched a major assault to retake Fallujah, the scene of deadly battles during the US occupation and one of the toughest targets yet in Baghdad's war on the Islamic State group. (Photo by Ahmad Al-Rubaye/AFP Photo)

A destroyed tank sits by the side of a road leading to Abi Adi, in the Tigray region of northern Ethiopia, on Tuesday, May 11, 2021. The Tigray People’s Liberation Front was on top of a coalition that ruled Ethiopia for nearly three decades. That changed in 2018, when Prime Minister Abiy Ahmed rose to power as a reformist. Abiy alienated the TPLF with efforts to make peace with its archenemy, Eritrea, and rid the federal government of corruption. (Photo by Ben Curtis/AP Photo)

Ali al-Naami, convicted of murdering his three daughters, is placed on a carpet to be executed at a public square in Sana'a, Yemen, 16 June 2021. Defendant Ali al-Naami, 40, convicted of killing his daughters Rahaf, 7, Raghad, 12, and Malak, 14, in June 2019, was executed by an executioner in front of hundreds of spectators in a public square in Sana'a. He had admitted to strangling them and drowning them in a water tank after the mother left the house due to domestic disputes with him. (Photo by Yahya Arhab/EPA/EFE)

A humpead wrasse, transported from Japan's southern island of Okinawa, swims with other tropical saltwater fish on display in a tank for the Sony Aquarium 2017 exhibition in Tokyo on July 31, 2017. The Sony Aquarium 2017 exhibition, featuring marine life common to the waters around Okinawa, runs until August 13. (Photo by Kazuhiro Nogi/AFP Photo)

A eight-metre-long Whale shark swims with other fish in a worlds' largest tank with its front panel size of 8.2 metre x 22.5 metre at the Okinawa Churaumi Aquarium on February 26, 2010 in Motobu, Okinawa, Japan. Japan's most popular aquarium attracts more than 2.5 million visitors per year. (Photo by Koichi Kamoshida/Getty Images)

A Sydney Aquarium diver uses a vacuum to clean the gravel in the Great Barrier Reef tank as a Ray Shark swims by September 26, 2006 in Sydney, Australia. The Aquarium is undergoing its annual spring clean to prepare for the school holidays using vacuums, along with sea creatures like Sea Cucumbers, Sea Urchins, Cleaner Wrasse Fish and Sea Stars to help complete the job. (Photo by Ian Waldie/Getty Images)

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

An Indian Sikh devotee takes a dip in the holy sarover (water tank) at the Golden Temple on the eve of “Ghallughara Diwas”, the 29th Anniversary of Operation Bluestar, in Amritsar on June 5, 2013. The 1984 assault on the Golden Temple complex by the Indian army was conducted in an attempt to arrest separatists Sikh leader Sant Jarnail Singh Bhindranwale and his militant followers who had initiated a movement for a separate Sikh state. (Photo by Narinder Nanu/AFP Photo)