• Aftermath of the 2017 Parsons Green bombing
  • Convicted terrorist Ahmed Hassan Mohammed Ali is jailed for life in London for one count of attempted murder and one of causing an explosion with intent to endanger life. He will have to serve 34 years before becoming eligible for parole. (Surrey Advertiser)
• Carcassonne and Trèbes attack
  • Four people are killed and 16 wounded when an extremist takes hostages in Trèbes, France. The suspect is killed by police. (BBC) (CNN)
• War in Afghanistan (2001–2021)
  • A car bomb is driven into a crowd outside the Ghazi Muhammad Ayub Khan Stadium in Lashkar Gah, Helmund, before detonating. At least 13 people are killed. (BBC)
• Northern Mali conflict
  • Malian Prime Minister Soumeylou Boubeye Maiga visits separatist rebel stronghold Kidal. (WBOY-TV 12 News)

• Economy of Denmark
  • Boeing loses a case in Copenhagen city court against the Danish Ministry of Defense over access to documents used in the purchase of Lockheed Martin F-35 Lightning II fighters in preference over Boeing F/A 18 Super Hornets. Boeing argued the evaluation process used in the purchase had been "flawed". (Reuters)

• 2018 disasters in Vietnam
  • A fire at a condominium complex in Ho Chi Minh City, Vietnam, kills at least 13 people and injures another 27, with most people dying of suffocation or jumping from high floors. (The Washington Post)

• Poland in the European Union
  • Polish Foreign Minister Jacek Czaputowicz asks the European Commission to halt its use of Article 7 of the Treaty on European Union against the nation in exchange for modifications to controversial proposed judicial reforms. (Radio Poland)
• Poisoning of Sergei and Yulia Skripal, Russia–European Union relations
  • The European Union agrees with the United Kingdom's assessment of the incident, stating that "there is no plausible alternative explanation" to Russian involvement. (NPR)
  • The EU ambassador to Russia is recalled from Moscow. (BBC)
• Iran–United States relations, Cyberwarfare in Iran
  • The United States charges and sanctions nine Iranians and the Iranian company Mabna Institute for hacking and attempting to hack hundreds of universities. (Reuters)
• Cyprus dispute
  • Turkey calls a statement of European Union support for Greek Cypriots in a dispute over offshore resources "unacceptable". Turkey has been using its Navy to prevent exploration by Cypriot vessels. (al-Jazeera)
• 2018 North Korea-United States summit
  • New US National Security Advisor John R. Bolton says that President Donald Trump should insist on Libya-styled denuclearization for North Korea. (Reuters)

• Crime in South Korea
  • Former President of South Korea Lee Myung-bak is detained on charges of taking bribes when he was in office. (Reuters)
• School shootings in the United States
  • One of the victims of the shooting at Great Mills High School in Maryland dies from her injuries. (CNN)
• Crime in the United Kingdom
  • Two lorry drivers receive prison terms, one of 14 years, for killing eight people when their vehicles collided with a bus on the M1 in Buckinghamshire, England, in 2017. (BBC)
• Russian interference in the 2016 United States elections
  • Tumblr shuts down 84 accounts linked to the Internet Research Agency. (The Outline)
• Gun violence in the United States
  • The US Department of Justice announces it will reclassify bump stocks as machine guns, effectively outlawing them. (Axios)
• Human rights in the United States, Transgender personnel in the United States military
  • US President Donald Trump issues an order banning "transgender persons who require or have undergone gender transition" from the military. Pentagon spokesman Major David Eastburn says this announcement will have no immediate practical effect for the military which will continue to recruit and retain transgender people in accordance with current law. (BBC) (NBC News)
• During a three-week US Border Patrol Operation Sandman near Yuma, Arizona, there are 204 arrests for human smuggling. (KYMA)

• 2017–18 Spanish constitutional crisis
  • Thirteen Catalan separatist politicians appear before the Spanish Supreme Court. Marta Rovira, who is "self-exiled" in Switzerland, does not attend. (AP via U.S. News & World Report) (The Washington Post)
  • The judge remands Jordi Turull, Josep Rull, Carme Forcadell, Dolors Bassa and Raul Romeva into custody again. (New York Times)
  • Judge Llarena reactivates the European Arrest Warrants against Carles Puigdemont, Marta Rovira, and four fugitive ex-members of dismissed regional government. (El Mundo)
• Abortion in Poland
  • Thousands protest across Poland against the government's proposed restrictions on abortion. (The Guardian)
• Resignation of Pedro Pablo Kuczynski
  • The Peruvian Congress votes 105–12 to accept President Pedro Pablo Kuczynski's resignation. (ABC News)
  • Vice President Martín Vizcarra is sworn in to replace Kuczyski. (The Guardian)
• Politics of the United Kingdom
  • Labour Party leader Jeremy Corbyn sacks Shadow Secretary of State for Northern Ireland Owen Smith after he called for a second referendum on European Union membership. He is replaced by Rochdale MP Tony Lloyd. (The Guardian)
• Government shutdowns in the United States
  • The United States government avoids another government shutdown when President Trump signs the 1.3 Trillion dollar omnibus spending bill into law. This bill ensures no more shutdown threats until October 1, 2018. (Federal News Radio), (The Washington Post)
• Politics of Mauritius
  • President Ameenah Gurib leaves the office after resigning on 17 March over a credit card from a NGO scandal. She is succeeded ad interim by Vice President Barlen Vyapoory. (Al Jazeera)

• Fauna of Australia
  • More than 140 pilot whales die in Hamelin Bay, Australia, after beaching themselves. (BBC)