SINGAPORE - The police are investigating after a Pasir Ris resident said she saw a drone fly past her window.

The police confirmed to The Straits Times on Wednesday (May 8) that a report had been lodged.

A check by ST on the Civil Aviation Authority of Singapore (CAAS) website found that the area where the drone was sighted was within 5km of an airport or airbase.

A Class 2 Activity Permit is required for unmanned aircraft activities conducted for recreational or research purposes in areas within 5km of where aircraft flight operations take place, according to the website.

In a Facebook post last Thursday, former piano teacher Amelia Yeo said that she had noticed something flying outside her toilet window when she was showering at around 5pm.

The resident at Belysa condominium said that her toilet window is always open as she lives on the 17th storey, adding that she assumed there were no privacy issues as "nothing is directly outside it".

Ms Yeo, 40, said that she saw the airplane-shaped drone fly past her window several times, about 50 to 100 metres away, at a "relatively slow speed".

She said that the last time she saw it, it was heading towards Elias Green condominium before flying back in the direction it had come from, which was towards Ris Grandeur condominium.

She told ST on Thursday: "It took me some time to realise it was a drone, as we always see planes as we are near the airport."

She said it was the first time she had seen a drone outside her flat, but that two of her neighbours, one on the same storey and one in the next block on the 16th storey, had also seen a drone on separate occasions.

Ms Yeo said that she made a police report upon the advice of her husband as well as the condominium chairman and the Pasir Ris Neighbourhood Police Post "immediately sent officers down to my place".

She said the officers told her they scoured the area but were unable to find the drone operator.

She said that the investigating officer had told her the drone flying was illegal on two counts as it constituted an outrage of modesty as well as a breach of no-fly zone laws.

Ms Yeo said that the next day, the police had told her that the case was reclassified as harassment instead of outrage of modesty.

"As for whether the drone managed to film anything else or invade anyone's privacy, I do not know," she added.

"The issue here is that it is illegal to be flying anything in this area," said Ms Yeo.

In September last year, a drone spotted flying around a Punggol Housing Board estate was being investigated by CAAS.