BIG NUMBERS are causing problems at Phuket Prison. There's the numbers explosion, with inmates numbering 1390 today in a jail built to hold 800 wrong-doers.

And there are the numbers of the mobile telephones that are hurled over Phuket Prison's high out walls . . . in greater numbers than ever before.

Phuket Prison's entire complement of prisoners and guards turned out to mark Chakri Memorial Day, the public holiday celebrating the rule of Rama I and his descendants that continues today. Westerners could be seen among the crowd.

Causing prison officers problems is the growing quantity of telephones being tossed into the prison. About 20 were thrown over the walls last month, and a Robinson department store bag containing a box of five mobile phones clattered to the ground on April 1.

At 4am today, despite more intense security, two small boxes each containing mobile telephones made sufficient noise when they hit the ground to bring officers to see what was happening.

New Phuket Prison Commander Rapin Nichanon oversaw today's ceremony then told Phuketwan that the families and friends of prisoners should be advised not to waste their time and money trying to give prisoners the means of illicit communication.

The mobiles thrown by the telephone tossers are new and used, and valued at up to 20,000 baht. Prison officers make a call phone available to prisoners if they need to contact the outside world, Commander Rapin said.

Sniffer dogs from police or the army are brought into Phuket Prison about once a month to search for drugs.