Rescuers are searching for survivors and there are reports of children trapped in a partly collapsed school.
The 7.1 magnitude quake caused damage in Morelos and Puebla states and in Mexico State.
It struck while many people took part in an earthquake drill exactly 32 years after a quake killed thousands.
The country is prone to earthquakes and earlier this month an 8.1 magnitude tremor in the south left at least 90 dead.
The epicentre of the latest quake was near Atencingo in Puebla state, about 120km (75 miles) from Mexico City, with a depth of 51km, the US Geological Survey said.
At least 149 people have died across the country, a civil protection agency spokesman said.
(Video : CNN)