Mexico City blast kills 25

The number of people killed by a blast in Mexico City at the headquarters of the state oil company, Pemex, has risen to 25, the interior minister has said. At least 100 people were injuredand an unknown number are trapped in rubble at the base of the 54-storey tower. The search for survivors continues. The cause of the blast is under investigation, Pemex says. Last September, 30 people died in an explosion at a Pemex gas plant in northern Mexico. Thursday's explosion in the lower floors of the building happened as shifts were changing in the afternoon, making the area particularly crowded. Television pictures showed debris from the blast spread out on to the street in front of the building, and Red Cross ambulances on the scene attending to the injured. Hundreds of rescuers helped by dogs are searching the building for around 30 people thought tobe trapped inside. Police have cordoned off the streets around the building, which is located in a busy commercial area of Mexico City. Pemex says its operations will continue to run normally - and commercial and financial obligations will continue to be met - despite the blast. The company's chief executive, Emilio Lozoya Austin, cut short a business trip to Asia and was onhis way back to Mexico, a Pemexstatement said. Relatives of employees have gathered outside the building in search of information about their loved ones, local media report. Some are said to have tried to reach employees on their mobile phones but have had no reply. "The place shook, we lost powerand suddenly there was debris everywhere. Colleagues were helping us out of the building," eyewitness Cristian Obele said. "We were talking and all of sudden we heard an explosion with white smoke and glass falling from the windows," another witness said. "People started running from the building covered in dust. A lot of pieces were flying."