The charges have prompted police to again urge parents and carers to monitor their child's online activities.

In April, detectives from the Child Abuse and Sex Crimes Squad's Child Exploitation Internet Unit (CEIU) began engaging online with a man from the Mid-North Coast.

Police will allege in court that the man believed he was speaking with a 13-year-old girl and engaged in conversations about sexually explicit acts.

Following extensive inquiries, a 31-year-old man was arrested south of Taree yesterday morning, Thursday July 18.

A search warrant was executed at a home and a number of electronic devices were seized for further forensic examination.

The man was charged with use carriage service to transmit indecent communication to a person under 16 years of age.

The man was granted strict conditional bail to appear before Forster Local Court on Tuesday, August 13.

In the second incident, earlier this month, detectives from the CEIU began engaging online with a man from Port Macquarie following a referral from the National Canadian Child Exploitation Co-ordination Centre (NCECC).

Police will allege in court that the man uploaded child abuse material to a social media site and believed he was speaking with a 51-year-old man in order to participate in sexually-explicit acts with a nine-year-old boy.

Following inquiries, detectives arrested a 21-year-old man at a home in Port Macquarie at about 7.30am on Friday July 19.

A search warrant was executed at the address and a number of electronic devices seized for forensic analysis.

The man was taken to Port Macquarie Police Station and charged with using a carriage service for child pornography and possess child abuse material.

He was refused bail to appear at Port Macquarie Local Court on July 19.

In the third incident, detectives from the CEIU began engaging online with another man from Port Macquarie.

Police will allege in court that the man believed he was speaking with a 14-year-old girl and engaged in conversations about sexually-explicit acts he wished to perform on the child.

Following extensive investigations, strike force detectives arrested a 23-year-old man at a home in Port Macquarie about 8am on Friday July 19.

Shortly after, investigators executed a search warrant at the address and seized several electronic devices which will undergo forensic examination.

The man was taken to Port Macquarie Police Station and charged with use carriage service to transmit indecent communication with person under 16 years.

He was granted strict conditional bail to appear before Port Macquarie Local Court on Wednesday, August 14.

Child Exploitation Internet Unit manager, Detective Chief Inspector Mick Haddow, said in today's electronic world, online safety is very important and parents need to speak with their children on a regular basis.

"With the number of online communication apps increasing, it is very important to speak to your child about the dangers associated with online conversations and know what your child is doing online," Mr Haddow said.

"These incidents are a timely reminder to keep an eye on how much time your child is spending on the internet, what websites they are visiting, and who they may be speaking with, as they may not be who they seem.

"Not only should young people be very careful about providing personal information details to a person they only know in an online environment, they should never organise to meet them as doing so may place them at further risk of harm.

"If they encounter something or someone they are not comfortable with, we encourage them to speak to someone they trust, who can then let our investigators know."

More information and educational packages for parents and children are available from ThinkUKnow, a multi-agency program designed to educate and promote cyber safety: https://www.thinkuknow.org.au/

Strike Force Trawler is an ongoing investigation by the CEIU into the sexual abuse and exploitation of children facilitated through the internet and related telecommunications devices.

Regular covert online investigations are conducted by the CEIU; and police in NSW work closely with their law-enforcement colleagues interstate and overseas.

Anyone with information about internet predators should call Crime Stoppers on 1800 333-000 or use the Crime Stoppers online reporting page.

Information provided will be treated in the strictest of confidence.