"I have been thinking of this for the last few days, after the bombing at the Hat Yai international airport, that I cannot sit idly by, because the incident is quite serious," the queen said.

"It will affect the tourism industry and the economy could collapse," she said.

The 72-year-old queen made the remarks during a heartfelt and deeply patriotic speech to some 1,200 village defense volunteers and scouts at the royal palace in Bangkok.

The 40-minute address was taped and broadcast on every Thai television station during prime time.

She made a similar appeal in November, after spending two months in the southern provinces along the Malaysian border, where a separatist insurgency has claimed more than 650 lives since January 2004.

Like her last address, the speech avoided any criticism of the government's handling of the unrest, while urging ordinary Thais to unite against violence.

"I do not incite you to arm and mount retaliatory killings ... but I plead to you all not to remain idle because this situation is very dangerous to our country," she said.

The village defense volunteer and scout system was created during the Cold War as an anti-communist measure, but continues to this day.

Queen Sirikit said the April 3 bombings in the southern commercial center of Hat Yai -- targetting an airport, a hotel and a department store -- showed the extent of the threat posed by the southern unrest.

"We have experienced a tsunami, which is very serious national calamity, but the bombs all over the south are more dangerous to our economy and Thailand because it severely affected the livelihood of the people," she said.

Nearly 5,400 people died when the December 26 tsunami struck six southern provinces in Thailand.

All rights reserved. © 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.