Disaster management minister Hachiro Okonogi said there are people buried under a collapsed building and authorities are working to confirm the details.
The train and subway service in and around Osaka, including the bullet train to Tokyo, was suspended while checks were made.
Students of a public elementary school in Ikeda city, Osaka Prefecture, evacuate to the school yard after a strong quake with a preliminary magnitude of 5.9 struck on Monday morning.
Private broadcaster TV Asahi showed firefighters responding to a blaze that broke out after the quake at a house north of Osaka city. In 1995, a magnitude 6.9 natural disaster killed more than 6,000 people when it struck in neighboring Kobe.
Brazilians seek revenge in Switzerland reunion
El Tri's form wasn't impressive heading into the World Cup , but they erased a lot of doubt on Sunday. But it was the football displayed by the American side that had the world at their feet.
The magnitude-6.1earthquake, initially measured at 5.9, struck the region, 400 kilometres west of Tokyo, during the morning commute. Dozens of flights in and out of Osaka were grounded and train service was suspended across a wide area.
The meteorological agency warned the quake might be followed by another big tremor in the coming days. NHK said an 80-year-old man and a 9-year-old girl had been killed by collapsing walls.
Some areas in Osaka are reportedly experiencing power shortage.
Chief Cabinet Secretary Yoshihide Suga told an emergency news conference that the government had received no reports of major damage due to the quake.
US to open temporary shelter in Texas for immigrant children
These children are "allowed outside, Chris, where we are, in the fresh air, for two hours a day", he said. How do the kids know where their parents are? Kennedy spoke to protesters in both English and Spanish.
The authorities said that none of the 15 nuclear reactors in this region have been affected by the quake.
Despite having a relatively low magnitude, the quake caused quite a shake, registering a lower six on the Japanese experiential scale of up to seven, meaning it is hard to stay standing. More than 170,000 homes were without power as of 8:20 a.m., regional utility Kansai Electric Power Co. said. An 84-year-old man in nearby Ibaraki died when a bookshelf fell on him at home, city officials say.
People are seen on a train in the Osaka Prefecture town of Shimamoto after it came to an emergency halt following a powerful quake that struck the prefecture and other areas of western Japan, shortly after 8:30 a.m. on June 18, 2018. "I thought it was a nightmare because I was so confused", she said.
Switzerland holds favoured Brazil to draw at World Cup
With World Cup time upon us, Rob Pizzo breaks down what you need to know about one of the biggest events in the world. Petersburg, while Switzerland faces Serbia in Kaliningrad on the same day.