The collapse of a dam in southern Brazil at an iron ore mine has left 121 people dead and 226 missing.
The collapse unleased a torrent of mining waste which buried the company's canteen and inundated neighbouring buildings in Brumadinho, in Minas Gerais state.
Authorities are still investigating the incident.
A spokesman for the Minas Gerais Fire Department said after a remembrance ceremony on Friday that authorities were not calling off the search for bodies although no one had been found alive since last Saturday.
On Friday, a ceremony was held to remember the victims of the mining dam collapse exactly a week after the disaster.
Dozens of people turned up to pay homage to those killed and missing.
The ceremony was held at the site of the disaster at around 1pm local time, the hour at which the dam breached a week ago, unleashing a destructive torrent of reddish-brown mining waste.
Diggers stopped work and rescue teams all looked to the sky as 10 fire department and police helicopters released flower petals on the iron ore mining complex.
A priest also gave a brief mass in front of a tall pink cross that had been planted in the mud.
"It is totally devastated, it looks like there has been a war," said 23-year-old Edvan Cristi, who lost friends who worked at the mine.
On Friday, operations seemed to enter a new phase as firefighters began excavating the mud with heavy machinery.
Previously, efforts had been focused on finding bodies closer to the surface.
The mud, which contains toxic levels of iron oxide, plastered 252 hectares of the adjacent city of Brumadinho and the Paraopeba River.
Vale SA, the company that ran and operated the dam, said the residues did not have dangerous levels of metals but experts argue that the impact on the environment could be irreversible.
Authorities and environmental organisations have begun testing water quality around the mining complex, while state and federal authorities have told residents to refrain from using water directly from the Paraopeba or 109 yards around it.
The Paraopeba River flows into the much larger Sao Francisco River, which could also be contaminated.
Hundreds of municipalities and larger cities such as Petrolina, 870 miles from Brumadinho, get drinking water from the Sao Francisco River.
The wave of mud is currently moving toward the Sao Francisco very slowly but officials hope the Retiro Baixo hydroelectric dam and plant complex about 185 miles from Brumadinho will prevent the mud from contaminating it.
The mud is expected to reach the Retiro Baixo dam between February 5-10.