Torrential rains that have plagued Brazil's northeastern Pernambuco state since Tuesday have left at least 34 dead, 29 of which occurred over the previous day, according to the latest official update.

"From last Wednesday until midday this Saturday, 34 deaths were recorded in the state," said the Civil Defense in a statement.

The most dramatic event occurred early Saturday morning when 19 people died in a major landslide in the Jardim Monteverde community, on the border between state capital Recife and the municipality of Jaboatao dos Guararapes.

Six others were killed in another landslide in the municipality of Camaragibe. Two died in Recife and another in Jaboatao dos Guararapes. 

Five others died earlier in the week, according to the Civil Defense.

Local press reports said three were killed by a landslide in Olinda, and a fourth person died after falling into a canal, also in Olinda.

The heavy rains have also forced almost 1,000 people to flee their homes due to the flooding and landslides.

President Jair Bolsonaro, in a tweet, expressed his "sorrow and solidarity to the victims of this sad disaster" and said his government will do everything possible "to alleviate the suffering."

He added that teams from the Armed Forces, the Ministry of Defense and the Ministry of Citizenship are being deployed "to assist in relief operations and provide the necessary aid to affected families."

Videos posted on social media show wide flooded avenues in several municipalities, collapsing houses and landslides.

According to meteorologist Estael Sias, of the MetSul agency, the heavy rains lashing Pernambuco and, to a lesser extent, four other northeastern states, are the product of a typical seasonal phenomenon called "eastern waves."

He explained that those are areas of "atmospheric disturbance" that move from the African continent to Brazil's northeastern coastal region.

"In other areas of the Atlantic this instability forms hurricanes, but in northeastern Brazil it has the potential for a lot of rain and even thunderstorms," he said.

-- 'Red alert' --
The National Institute of Meteorology (Inmet) maintained its "red alert" through Sunday in Pernambuco, its highest level of warning for flooding and landslides.

Between Friday night and Saturday morning, the volume of rainfall reached 236 millimetres (nine inches) in some parts of the Pernambuco capital, according to the mayor's office.

That is equivalent to more than 70 percent of the forecast for the whole month of May in the city. 

The Pernambuco Water and Climate Agency said the situation could worsen as rain will continue for the next 24 hours in the state.

Over the past year, hundreds of Brazilians have died in flooding and landslides brought on by torrential downpours.

In February, more than 230 people were killed in the city of Petropolis, the Brazilian empire's 19th-century summer capital, in Rio de Janeiro state.

Heavy rainfall turned streets in the area to gushing rivers and triggered landslides in poor hillside neighborhoods that wiped out virtually everything in their path.

Early last month 14 more people were killed, also by flooding and landslides in Rio de Janeiro state.

The victims included a mother and six of her children, who were buried when a landslide swept away their home, officials said.

Experts say rainy season downpours in Brazil are being augmented by La Nina -- the cyclical cooling of the Pacific Ocean -- and by climate change.

Because a hotter atmosphere holds more water, global warming increases the risk and intensity of flooding from extreme rainfall.