Before doing this, officers need not issue a notice to people responsible for the premises.

A Health, Welfare and Food Bureau spokesman said hygiene officers would apply for a court warrant only when they could not contact the occupier or owner of the property where mosquito-related health hazards were present.

'Mosquito-related health hazards' refer to potential mosquito breeding grounds found within 500 metres of a recent local or imported case of dengue fever. It also applies to those within 2 kilometres of a recent local case of Japanese encephalitis and any areas where ovitrap indices were above 40 per cent.

The indices represent the proportion of traps found to contain eggs of the Aedes albopictus mosquito. This is the species which transmits dengue fever.

'If the department could contact the relevant occupier, owner or manager of the land before it obtained a warrant and entered the property, it would ask them to remove the accumulated water on their own as far as possible,' the spokesman said.

He added that the government would recover costs of operations from occupiers, owners and those managing the premises.

The new law also stipulates the managers of a property are liable for mosquito breeding grounds.

'The success of anti-mosquito work hinges on the co-operation of the government and the public. People should always clear accumulated water and take appropriate measures to prevent mosquito breeding,' the spokesman added.

There is growing concern in Southeast Asia about the spread of mosquito-borne diseases such as dengue fever, which have in recent years have killed hundreds of people.