Seasonal rains have triggered massive flooding in Indonesia's capital, triggering the evacuation of at least 20,000 people and bringing misery to many more.

Floods regularly hit parts of Jakarta in the rainy season, but Thursday's inundation following an intense rain storm appeared especially widespread.

Authorities said four people had been killed by the waters, which washed into homes, offices, schools and roads across the city of 14 million people.

Al Jazeera's Step Vaessen, reporting from Jakarta, said the entire city is currently flooded.

"People cannot get to their offices. They are walking or attempting to use bikes to get to work," she said.

"In all the years of flooding, and the city receives floods every year, it has never been this bad, and it is a lot more serious."

Vaessen, who reported that water levels are up to four metres higher than the day before, said that it was also an economic disaster for the city.

Monsoon rains, deforestation in the hills to the south of the city, chaotic planning and hundreds of rivers and waterways combine to cause floods, which expose the country's poor infrastructure even as it posts impressive economic growth.

Source: Al Jazeera and agencies