(Recasts with seven rescued) LAGOS, Nov 28 (Reuters) - Seven people were rescued from the rubble of a collapsed building in Nigeria's largest city on Tuesday, but rescue workers said they lacked heavy diggers to determine if more were still trapped. Volunteers using shovels pulled the survivors out of the remains of the three-storey building in Lagos and were still awaiting the arrival of excavation equipment as night fell. "Seven people were rescued. Two were not injured and five are receiving treatment," said Attah Benson of the Red Cross. "We have to assume that there are more people trapped until we have excavated the rubble because we have no information on how many were there," he added. It was not clear what caused the collapse of the building, which was still under construction. Most of those inside were builders sleeping on the site. Building regulations are weak and emergency services barely operate in Nigeria, where the government is crippled by rampant corruption and inefficiency. At least 28 people were killed in July when a four-storey building collapsed in Lagos. Authorities blamed that disaster on substandard building materials.
