Mexico’s volcano dramatically erupted on Thursday lighting up the sky with incandescent rocks and forcing flight delays.

Flights to and from Mexico City’s international airport, were halted on Thursday morning as a precautionary measure, a government official said.

Mexico City airport spokesman, Jorge Andres Gomez, said American Airlines, US Airways, Delta Airlines and Alaska Airlines suspended flights, as well as Aeromexico.

Over the last few hours, 99 exhalations of ash, vapour and gas were reported, accompanied by 12 hours of high to medium frequency tremors, Mexico’s National Centre for Disaster Prevention reported.

The volcano is on yellow phase two alert, the second-highest warning on the centre’s seven-step scale.

Civil protection authorities from Mexico City have met with the state of Mexico, Puebla, Morelos, Tlaxcala as well as authorities from the National Defense, Navy and federal police forces to determine whether the volcano alert should be changed in the coming hours.

With up to 50,000 residents across 24 towns at risk from volcanic gases and lava flow, authorities are keeping a close watch over Popocatepetl.

The 5,450-metre (17,900-foot) volcano, whose name means “Smoking Mountain” in the Nahuatl Indian language, lies just 64 kilometres (40 miles) southeast of Mexico City and its 18 million residents.