However, by late Saturday rescue workers had not found any sign of the minibus or other possible victims, Juarez said.

 

The crater swallowed dump trucks and tied up traffic for miles in South America's biggest city.

 

Two cars were removed from the rubble. A crane on the edge of the hole threatened to topple over but was stabilised overnight, the public security department said.

 

More than 200 people living near the site were evacuated and put up in hotels because of fears that the crater could expand, threatening to swallow their buildings.

 

Local media reported three construction workers were hurt in the incident, but firefighters and the state-owned Sao Paulo subway company did not confirm the injuries.

 

The cause of the collapse was under investigation, but the consortium of Brazilian companies building the subway station said in a statement that heavy tropical rains this year may have contributed by softening the underground area around the construction site.