A 6.1 magnitude earthquake has struck southern Mexico, the third to hit in the country in as many weeks, causing panic and forcing people out onto the streets.
At least four people died - two of heart attacks in Mexico City where a tremor was felt.
The other victims were from the municipality of Asuncion Ixtaltepec in Oaxaca. One man died there when his house collapsed.
The latest quake hit at 7.53 local time and had a depth of nine kilometers.
Its epicenter was located seven kilometers west of Union Hidalgo near the town of Matias Romero in Oaxaca, according to the National Autonomous University of Mexico City’s National Seismology Service.
SISMO Magnitud 6.1 Loc. 7 km al OESTE de UNION HIDALGO, OAX 23/09/17 07:52:59 Lat 16.48 Lon -94.90 Pf 75 km— Sismológico Nacional (@SSNMexico) 23 September 2017
The nation's disaster agency says it was an aftershock of the magnitude 8.1 earthquake that hit the state on 7 September, in which at least 90 people died.
A series of 4.0 magnitude earthquakes have been reported off Oaxaca’s coastline during the night. Juchitan, the city in Oaxaca that suffered the most destruction and deaths during the earlier quake, has registered three more between magnitudes 4.8 and 5.0.
The Mexican President Enrique Pena Nieto said structures which were affected by the previous quake have suffered more damage including the bridge of Ixtaltepec.
Al momento, las mayores afectaciones son el puente de Ixtaltepec, que deberá reconstruirse, y estructuras con daños previos que colapsaron.— Enrique Peña Nieto (@EPN) 23 September 2017
Mexico City did not immediately appear to sustain significant damage, the country's office of the secretary of public security said.
But rescue efforts at a collapsed residential building in the Tlalpan neighborhood of the Mexican capital were suspended because of a risk that buildings already impacted by Tuesday's quake could collapse.
Operations are ongoing at some of the dozens of houses and offices which were hit by and they could last "for at least two more weeks," Luis Felipe Puente, Mexico's civil protection coordinator, told CNN affiliate Foro TV.
The 7.1 magnitude earthquake devastated the country's central region. At least 307 people died and dozens are still missing.