Leading Myanmar exile media organisations said their websites had been crippled by cyber attacks today, on the third anniversary of a crackdown on the "Saffron Revolution" monk-led protests.

The Internet sites of the Democratic Voice of Burma, the Irrawaddy Magazine and the Mizzima news service were overwhelmed by a flood of incoming messages known as a Distributed Denial of Service (DDoS) attack.

"All the fingers are pointing at the regime and regime-hired mercenary hackers -- these are the people who are behind the attack I'm sure," Aung Zaw, founder and editor of the Irrawaddy, told AFP.

There was a similar attack on the main exile media in September 2008, on the first anniversary of the Saffron Revolution, which crippled websites for several days.

Toe Zaw Latt, the Democratic Voice of Burma's Thailand bureau chief, said the Norway-based group was now better prepared to cope with cyber attacks, and had restored its site on Monday after an 18-hour interruption.

The 2007 protests in Myanmar began as small rallies against the rising cost of living but escalated into huge anti-government demonstrations led by crowds of monks.

At least 31 people were killed by security forces while hundreds were beaten and detained in a crackdown by the authorities on the protests