Rescuers trying to enter a flooded Mexican coal mine where 10 workers have been trapped for more than a week have encountered obstructions blocking their advance, authorities said today.

A soldier wearing a helmet and military fatigues and equipped with a scuba tank descended into one of the mine shafts in a metal cage on Wednesday, emerging minutes later visibly wet.

The rescue team made four attempts to explore the crudely constructed El Pinabete mine in the northern state of Coahuila, but debris prevented them from entering the main tunnel below, officials said.

"They found that they don't have room to move forward. There are obstructions," Defense Minister Luis Cresensio Sandoval said.

Rescuers would keep trying to gain access, the general told reporters in Mexico City.

Five workers managed to escape in the initial aftermath of the accident on August 3, but there has been no contact with the others.

Two underwater drones have been deployed in the operation in Agujita, as have hundreds of soldiers and other rescuers, 25 water pumps and seven drills.

According to authorities, the flood occurred as miners were carrying out excavation work and hit an adjoining mine full of water.

The focus so far has been on pumping out water from the 60-meter (200-feet) deep mine.

The water in the shafts had fallen significantly, from more than 30 meters, but was still several meters deep, authorities said.

"We will be evaluating it throughout the day. We have to be careful not to endanger anyone," civil defense national coordinator Laura Velazquez said.

A soldier takes part in an operation attempting to reach 10 miners trapped in a flooded coal mine following a landslide a week ago, in the community of Agujita, Sabinas Municipality, Coahuila State, Mexico, on August 11, 2022. - Hundreds of soldiers and other rescuers are taking part in efforts to save the miners. Five workers managed to escape from the crudely constructed mine in the initial aftermath of the accident on August 3, but there has been no contact with the others. (Photo by Pedro PARDO / AFP) (Photo by PEDRO PARDO/AFP via Getty Images)

Prosecutors have announced an investigation into the accident, the likes of which are common in Coahuila, Mexico's main coal-producing region.

The worst was an explosion that claimed 65 lives at the Pasta de Conchos mine in 2006.

Frustration was growing in the tight-knit mining community with each passing day.

"It's been eight days now. We're running out of hope because they (authorities) don't give us any information to give us hope," a miner and volunteer rescuer who did not want to be named told AFP.

The government's announcement yesterday that rescuers were close to entering the mine was greeted with caution by anxious relatives.

"Let's hope that now it's true. Every day they say the same thing," said Juan Orlando Mireles, whose father is among the missing.