Security forces in southern Thailand were put on full alert to counter any attacks by Islamist insurgents on the anniversary of a mosque siege when more than 100 people died, officials said Sunday. The alert was ordered after intelligence reports indicated separatist insurgents were planning to stage attacks on the fourth anniversary of the Krue Se mosque siege, said army spokesman Col. Akara Thiprote. On April, 28, 2004, several hundred young Muslims stormed security outposts and seized the mosque. In the counterattack, 107 Muslims, some believed to be insurgents, were killed. For many Muslims, the mosque has become a symbol of the heavy-handed tactics of Thai authorities as they try to suppress an insurgency that has taken the lives of more than 3,000 people since early 2004. Many Thai Muslims say they are treated as second-class citizens in a country where Buddhists are dominant. The Thai government has attempted to soften its approach with a "hearts and minds" campaign, but daily bombings and shootings still occur in the south.