According to the police the suspects had stolen the items last month but they were later recovered.
The police said that a buoy which was stolen was used to provide weather information as well as tsunami alerts.
All five suspects are residents of Devinuwara in the Matara area. The suspects are to be produced in court today.
Tsunami buoys are anchored buoys that can detect sudden changes in undersea water pressure and are used as part of tsunami warning systems in the Pacific Tsunami Warning Center and Indian Ocean.
A devastating Indian Ocean tsunami in 2004 killed thousands in Sri Lanka as the island was not prepared to alert people living along the coast.
However since then the Sri Lankan government has invested on new tsunami warning equipment and also conducted several drills for the public on the precautions they need to take in the event of a tsunami alert.
Sri Lanka was alerted on a possible tsunami just last week following a massive quake off Sumatra, Indonesia.
Mass evacuations were carried out along the entire coastal belt of Sri Lanka following the alert. The tsunami alert was however lifted after a couple of hours. (Colombo Gazette)