Ukraine and Russia have continued striking each other overnight, with Volodymyr Zelensky accusing Moscow of using North Korean missiles. The Ukrainian president said strikes in Zaporizhzhia - which killed at least six and injured at least 19 - involved ballistic missiles from Russia's ally. In Voronezh, in southern Russia, warehouses belonging to the online retailer, Wildberries, were hit by Ukraine. The company, known as Russia's Amazon, has been repeatedly targeted in recent weeks. The attacks come a day after at least 13 people were killed, including one child, in Ukrainian drone strikes on the Russian republic of Tatarstan, more than 1,100 km (680 miles) from the Ukrainian border.

Laser weapons are on a roll. The U.S. Air Force, Army, Navy, Marines, and the Joint Improvised-Threat Defeat Organization are testing them. Plans include mounting them on Humvees to shoot down drones. You can see them destroy drones on YouTube. The Missile Defense Agency wants to test laser-equipped drones as a defense against North Korean missiles.

In this April 30, 2015, file photo, Tesla Motors CEO Elon Musk unveils the company's newest products, in Hawthorne, Calif. In this April 30, 2015, file photo, Tesla Motors CEO Elon Musk unveils the company's newest products, in Hawthorne, Calif. One of Tesla CEO Elon Musk's companies, the nonprofit start-up OpenAI, manufactures a device that last week was victorious in defeating some of the world's top gamers in an international video game (e-sport) tournament with a multi-million-dollar pot of prize money. We're getting very good, it seems, at making machines that can outplay us at our favorite pastimes. Machines dominate Go, Jeopardy, Chess and -- as of now -- at least some video games.