They also cited increased demand from clients seeking short-term summer holiday ayis for children at home.

The floods in Anhui and Jiangsu blocked ayis trying to get to the city for work, according to Shanghai EJLL Home Economic Service Co Ltd.

"We have a training center in Anhui Province and we had intended to bring about 300 ayis to the city this month, but now none of them has come," said Xia Jun, director of the company.

Xia said many ayis had told the company they were not able to leave their homes because of flooded streets.

He said the company was looking for ayis from Jiujiang, Jiangxi Province, but that province was also flooded.

"We have to explain to our customers, persuading them to overcome the summer holiday difficulties by themselves," he said.

EJLL said it won't charge clients more during the shortage, but another company, the Shanghai Best Homemaking Service Co Ltd, said each family will have to pay an extra 100 yuan (US$13) to 200 yuan a month.

The situation is expected to improve at the end of the month, companies said.