Emergency communications officer (ECO) Mohamad Suhaimi Ami once took a 999 call from a woman who wanted to order a pizza.

He told her she was calling the police line, but she nervously repeated that she wanted to order a pizza.

Mr Mohamad Suhaimi, who has been with the Police Operations Command Centre (POCC) for about seven years, quickly realised that the woman was in distress and trying to get help, but was unable to speak freely over the phone.

He began to ask her yes-and-no questions which provided more information on her plight.

"Using the topic of ordering food, I got more information, including her address, and the police were dispatched to the location," he said.

More details of the case could not be provided due to operational secrecy, but the police said the case was dealt with.

Mr Mohamad Suhaimi added: "For some calls, you need to pick up on the signs. Some people don't have the opportunity to tell you straight about the problem."

ECOs at the POCC are trained to identify coded messages from those in distress, and have to clear an internal competency test before they are allowed to handle live 999 calls.

This is crucial as the POCC handles more than one million 999 calls a year. Last year, it recorded about 1.19 million calls, or more than 3,000 a day.

But more than 60 per cent were nuisance calls, including those made by wilful children and callers who kept silent over the phone.

Officially launched in 2015, the POCC is the nerve centre of the Singapore Police Force's operations, working proactively to detect crime, deploy front-line officers, and support responding officers with findings from sense-making.

The centre has progressively upgraded its capabilities and now houses liaison officers from Home Team agencies such as the Central Narcotics Bureau, Immigration and Checkpoints Authority, and the Singapore Civil Defence Force.

Those at the centre are split into three functional groups.

The Emergency Communications Group consists of ECOs who handle all 999 calls and text-based reports.

The Incident Watch Group consists of watch officers who make an assessment of the information routed from the ECOs and dispatch the appropriate resources to an incident scene.

The group also maintains oversight of all live incidents, keeping close communication with and supporting front-line resources.

The third group is the Sense-making Group, comprising officers who form an incident picture through the use of 90,000 police cameras (PolCams) islandwide, social media and other screening systems.

Working with the information from the ECOs, the Sense-making Group is able to form a situation picture, even while the caller is still on the line.

Superintendent of Police Nini Chow, 51, watch commander at POCC, said sense-making begins the moment a 999 call is received.

"The POCC is equipped with sense-making capabilities which provide a situation picture to responding front-line resources in advance," she said.

"This allows ground commanders to have a better appreciation of the situation at the incident location so that they can deploy resources quickly and effectively manage the incident."

Previously, incidents were handled sequentially instead of concurrently, by first deploying officers to the scene. Attempts to make sense of the situation usually happened only after gathering information on site.

But nuisance calls remain a concern.

Mr Mohamad Suhaimi said the volume of such calls is a worry and urged the public to call 999 only in an emergency.

"I'm afraid that when there's an emergency call coming in, that those in genuine need will be unable to reach us," he said.

"We are here to protect lives. The public needs to know that calling the emergency line should really be only for emergency use."