Rescuers were searching for survivors in basement of the large office tower, Osorio Chong said.

CNN: STORY HIGHLIGHTS

At least 80 people were injured in the Mexico City blast, Interior Minister Miguel Angel Osorio Chong told reporters.

CNN: STORY HIGHLIGHTS

The government of former president Felipe Calderon stopped releasing figures of drug-related violence in September 2011, but Interior Minister Miguel Angel Osorio Chong said the federal government had continued to keep a tally.

BBC: Mexico government says drug-related murders down by 14%