SINGAPORE - The police are investigating an incident at a HDB block in Ang Mo Kio, where a man allegedly climbed from outside a 12th-storey flat down to the 10th floor early Wednesday (June 29) morning.

The owner of the flat, who wanted to be known only as Mrs Lee, told Shin Min Daily News that she was reading the papers in her living room at around midnight when she heard strange noises coming from her kitchen window.

"I thought it was a neighbour hanging clothes, but when I entered the kitchen to take a look after the noise continued, I saw a man outside the window," said the 40-year-old.

The man, who was naked from the waist up, was holding onto the window frame as he balanced on the clothing rack.

Mrs Lee called for her sleeping husband, who rushed into the kitchen to find the man still perched outside the window.

Mr Lee, 50, said: "I asked the man what was he doing and he replied 'sorry, sorry', before he started climbing downwards.

"I watched him climb down quickly and enter a unit on the 10th floor."

Worried that the man might have been a burglar, Mrs Lee subsequently called the police.

In response to queries, a police spokesman confirmed the incident at Block 225, Ang Mo Kio Avenue 1, and said it had classified the case as intentional harassment.

While the man had disappeared when police officers checked on the 10th floor unit, they found contraband cigarettes inside.

The Singapore Civil Defence Force (SCDF) said it was alerted to the incident at 12.37am and dispatched a fire engine, a red rhino, two support vehicles and an ambulance to the scene.

An SCDF spokesman said a safety life air pack was deployed at the foot of the block as a precautionary measure.

According to residents living on the 10th floor, the unit was rented out to two young Vietnamese tenants about a month ago.

They also claimed to have seen several strangers, carrying suitcases and bags, visiting the unit at odd hours over the past two weeks.