Officials and weather forecasters from Foshan Observatory in this Pearl River Delta city are under fire after only sending warnings to officials and paid customers before a deadly hailstorm hit the area last month.

At least 15 people were killed and many houses destroyed or damaged after the storm struck Foshan's Shunde district on April 17.

At the news conference held afterward, the district's observatory said it had successfully forecast the storm. Besides broadcasting the forecast via TV and radio, it sent warning messages to 300,000 mobile phone subscribers on April 15, and to about 3,000 officials and village heads on April 16 and 17.

This kicked off a storm in the real and cyber worlds with residents questioning why the observatory only informed selected receivers, and netizens expressing dissatisfaction over the observatory's service.

Related officials and weather forecasters from the observatory explained that they sent the special weather forecast to officials in charge of water conservancy, school headmasters, overseers of construction sites and village chiefs one day in advance to let the officials and related persons organize residents, workers and students to prevent and fight the disaster, avoiding and reducing casualties and minimizing the economic loss.

"The observatory doesn't have sufficient capacity to send the weather forecast to all mobile phone users at the same time," officials said.

Shunde district is a major manufacturing base in Guangdong province, which borders the Hong Kong and Macao special administrative regions. The prosperous district has a population of more than 2 million.

"And those who refuse to pay for the service might think the weather forecast text messages are spam," officials added.

Many local residents, however, refused to accept the observatory's explanation.

Li Dewei, a Foshan white-collar worker, said the observatory has the duty to reveal accurate weather forecast in a timely fashion and try to let everyone know.

"The observatory should expand its message-sending capacity and improve service if it is found to have deficiencies," Li told China Daily.

"The observatory should publicly apologize for its mistake, instead of making excuses," he said.

Wang Chenjuan, a local housewife, said the observatory might have discriminated against the poor and those who have no official power.