The mayor’s office says an unknown number of people are trapped under the rubble after an explosion hit a market in Yerevan. At least one person has been killed and an unknown number of people are believed to be trapped in the rubble after a powerful explosion ripped through a retail market in Armenia’s capital Yerevan, officials said. Rescue crews were working to pull people out of the rubble, Levon Sardarian, a spokesman for Yerevan’s mayor, told the Associated Press news agency. Maria Titizian, a journalist based in Yerevan, said the market building collapsed and was still burning. The death toll is expected to rise, he said. “It’s a very busy market in the afternoon so at the moment it’s hard to give exact numbers,” he said. “According to the ministry in charge of emergency situations, the fires started where fireworks are sold, they believe that was the cause of the explosions, but at the moment it cannot be confirmed,” Titishian said. The Ministry of Emergency Situations said there were 10 fire engines at the scene and another 10 were heading to the Surmalu market, located about 2 kilometers (1.2 miles) south of the city center. The cause of the explosion was not immediately known. Photos and videos posted on social media showed a thick column of black smoke over the market as successive explosions rang out. The emergency ministry said at least 20 people were injured in the explosion.