A volcano southeast of the Mexican capital spewed more gas and ash into the sky on Tuesday as authorities maintained their warning level at one step below red alert.

The only time the Popocatepetl volcano triggered a red alert on the government’s stoplight-style system since emerging from decades of dormancy in 1994 was in 2000. The volcano’s last big eruption was more than 1,000 years ago.

The 5,425-metre (17,797-foot) mountain just some 70km (45 miles) southeast of Mexico City and known affectionately as El Popo, has been belching for days, dusting towns and crops in Puebla state in superfine ash.

“When nothing is happening we worry,” said a cheerful Viridiana Alba, who has been selling flowers in Amecameca’s central plaza for 25 years. El Popo rises directly across from her stand.

“We know that right now it’s releasing smoke, that’s freeing the energy that it holds,” she said. Ash still rests on the awning that shades her plants from when the wind blew her way last weekend. The town was shaken by the volcano’s tremors, but as long as the ash remains light she believes it will help her plants.

Winds have blown a large plume of ash east over Puebla and Veracruz states and eventually the Bay of Campeche and beyond.

Mexico’s National Center for Prevention of Disasters said in its report on Tuesday that small domes of lava continued forming inside the crater that were then being destroyed by small and moderate explosions. It advised that people living in communities near the volcano would likely continue those explosions over the coming days and weeks.

No evacuations have been ordered, but authorities have been driving evacuation routes, preparing some shelters and doing simulation drills.

On Cortes Pass, a small highway that crosses a saddle between Popocatepetl and the inactive Iztaccihuatl volcano, a couple of dozen civil defence vehicles and soldiers blocked the way Tuesday.

The road was closed to traffic and most of the cabins that draw tourists were empty.

Cástula Sánchez, 75, who sells food to tourists on the weekends, was confident Popocatepetl would settle down again and the tourists would return. She lives in nearby San Pedro Nexapa where three decades ago lava arrived close to her home before they could evacuate, but they were spared.

Now she runs a local information service from the back of her shop. Residents bring her short messages scribbled on a piece of paper that she then reads over a loudspeaker the whole community can hear. So far authorities have asked nothing of her, just to keep an eye out.

In Amecameca, police handed out pamphlets with tips on being prepared in case the volcano’s activity increased. The pamphlet recommended having important documents at hand, a full gas tank, masks and towels to dampen if residents had to leave in a hurry.

The activity this time has not been significant for locals so far, but the localised effects could be real for residents on one side of the volcano while everything is normal on the other.