The photo taken on Jan. 25, 2019 shows a helicopter flying over the site of the collapse of a dam in Brumadinho Municipality in the southeastern state of Minas Gerais, Brazil. About 200 people were missing after a tailings dam owned by Brazilian mining giant Vale collapsed Friday in the southeastern state of Minas Gerais, said local fire department. (Xinhua/AGENCIA ESTADO/O Tempo/Moises Silva)

RIO DE JANEIRO, Jan. 25 (Xinhua) -- About 200 people are missing after a tailings dam owned by Brazilian mining giant Vale collapsed Friday afternoon in southeastern state of Minas Gerais, said the local fire department.

The dam collapsed in Brumadinho Municipality and caused a mud wave to flow down the river, destroying administrative areas of Vale and residential areas as well.

As the disaster occurred close to lunch hours, many workers are believed to have been inside a refectory area which was completely destroyed by the mud wave.

In addition to those missing, four people were rescued from the affected area and taken to nearby hospitals, according to rescuers.

Residents told local media that there were no warnings before the mud wave and no sirens which could have given residents some time to flee.

Aerial images of the area show that bridges on a railway and a highway were destroyed, which affects the access of more rescue workers to the impacted area.

A couple of hours after the collapse, the mud wave reached the Paraopeba River, which runs through the town center of Brumadinho.

The town center of Brumadinho has been evacuated by local authorities, since the river often overflows when it rains heavily.

The Brazilian government has announced a crisis cabinet to deal with the environmental disaster caused by the collapse of a tailings dam.

Through his social networks, President Jair Bolsonaro said the ministers of environment, mines and energy, and regional development were heading to the region.

He also said in an interview to a local radio that "something was being done in a wrong manner through the years."

Bolsonaro said that the similar accident in Mariana, also in Minas Gerais state, should have worked as a warning.

In November 2015, a tailings dam collapsed in Mariana killed 19 people and caused unmeasurable environmental and economic damage. It was considered the worst environmental disaster in Brazilian history.

According to presidential spokesperson Otavio Rego Barros, Bolsonaro himself may head to Brumadinho on Saturday. However, that remains unconfirmed, as Bolsonaro is scheduled to travel to Sao Paulo this weekend to undergo surgery on Monday to reverse a colostomy he underwent in September after he was stabbed at a campaign event.