The force of the crash set two dozen cars ablaze and pieces of wreckage were strewn across a wide area, Tellez said, adding that at least 40 people were injured in the incident.
Ebrard said five people on the ground who were seriously injured were taken to hospital and that a fire set off by the accident was under control.
About 1,800 people were evacuated from the area.
Civil aviation officials are investigating the cause of the accident.
Mexican radio reported an air traffic controller as saying that the government Learjet was coming in to land at Mexico City airport when it hit the ground between tall buildings in a busy business district.
"When it was at approximately [4.8 kilometers from the airport] they reported an emergency, they didn't say what kind of emergency, and we lost all contact with them," Angel Iturbe, the controller, said.
Vasconcelos was, until recently, a key player in Mexico's army-led war on drug cartels reportedly behind the killings of more than 4,000 people this year of mainly drug traffickers but also enforcement officers.