The search for mosquito-breeding spots has intensified in Toa Payoh Lorong 8, after an elderly man who lived in the estate died of dengue fever on Saturday.

The Potong Pasir Town Council has stepped up checks on drains and other common breeding areas.

Mr Sitoh Yih Pin, the MP for Potong Pasir, said residents will be informed of any updates. "If need be, notices will also be put up in affected areas as soon as problem areas are identified," he said.

The National Environment Agency (NEA) said Toa Payoh Lorong 8 was a former dengue cluster, which had seven reported dengue cases before the cluster was closed on Nov 23. A cluster is closed by NEA when it has fewer than two cases over two weeks.

During its earlier inspections of the area, the NEA found 11 Aedes mosquito breeding habitats and destroyed them. Four were found inside homes, while the other seven were found outdoors. The NEA said it will continue to inspect the area.

Mr Sitoh yesterday urged residents to report potential breeding areas to the authorities.

Across Singapore, 254 dengue cases were reported in the week ending Nov 21, up from 198 the week before. From Nov 22 to last Friday 3.30pm, 228 cases were reported. As of last Friday, there were 39 active dengue clusters. The largest, in the area from Tampines Street 81 to Tampines Street 91, had 42 dengue cases in the last two weeks.

The NEA and Ministry of Health said on Sunday that warmer conditions caused by El Nino could result in shorter breeding periods for Aedes mosquitoes and shorter incubation times for the dengue virus.

Retiree Tan Soon Seng, 78, from Block 224, Toa Payoh Lorong 8, said he often applies insect repellent. He is worried construction work under his block has stopped for a week. "I'm afraid this may result in the collection of stagnant water and cause mosquito breeding."