I've lived here all my life and I don't feel like there's any danger

Daniel Viscaino, local resident

Scientists say that a huge dome of lava has developed inside the crater and that pressure building up underneath means it is likely to either explode or collapse within days or weeks.

An exclusion zone has been set in place around the volcano, with non-residents not allowed within 11.5 km (seven miles) of the crater.

Troops on guard

The volcano, known as the Volcano of Fire, is 3,820 meters (12,533 feet) high.

An explosion of the expanding lava dome would cover the surrounding area with rock and ash, but if the dome collapses scientists are predicting that rivers of molten lava would flow down the southern slopes.

Soldiers are guarding the perimeters of the prohibited area and patrolling the streets of nearby villages and towns in case evacuation becomes necessary.

Volcanologists have said that, for now, seismic activity in the area is remaining stable and white plumes of smoke seen above the crater are a sign that some of the pressure is escaping.

Residents unconcerned

And the villagers who live near the volcano seem unconcerned despite the possibility of an eruption.

"I've lived here all my life and I don't feel like there's any danger," said 40-year-old Daniel Viscaino, resident of the village of La Becerrera, about 10 km (six miles) from the crater.

"As long as the smoke is coming out like that nothing's going to happen," he added.

Volcanologists consider the Colima volcano the most active in a chain of nine volcanoes located across the middle of Mexico.

In 1998 explosions sent lava flowing five km (three miles) down the side of the volcano forcing 500 people in nearby villages to flee.