Hackers have brought down the International Women’s Day website today, the 100th anniversary of the event.

Three separate "denial of service" attacks have been directed at the internationalwomensday.com website since last night, the organisers confirmed.

"As the Centenary of International Women's Day (IWD) struck in the Asia Pacific region, perpetrators commenced attacking the internationalwomensday.com website in an explicit attempt to prevent users from accessing the global hub for International Women's Day," a statement said.

Women's groups, charities, governments, companies, schools, universities, the media and women around the world will take part in some 2,000 events around the world to mark the occasion today. Many other events were scheduled online.

Australian entrepreneur, campaigner and founder of the website, Glenda Stone, said: “We are monitoring the attack but women’s spirits will not be dampened by the malicious attempts of those who do not support International Women's Day.

"Activity around the world will continue to mark the day's significance as millions of women rise to campaign for equality and celebrate achievement."

The first attack brought the site down for about an hour last night, but two subsequent attacks this morning rendered inaccessible for some time.

The site expected over 100,000 visitors today alone and has recently had about 25,000 users a day.

According to the International Women's Day organisers, the attack on the site was a denial of service (DoS) attack.

They said it had been the target of "a massive 5 gigabytes per second" directed at the site in an explicit attempt to prevent "legitimate users" from accessing it.

"These type of attacks have brought many leading websites around the world to their knees."

Sites affected by such denial of service attacks have included the website of the Central Applications Office. In August last year, the site was brought down twice in a week as students attempted to access their third level course applications. Passwords were reissued to 22,000 students as a result of the attack.

The situation with regard to the International Women's Day website was being "monitored closely", organisers said.

* See below for a two-minute short, specially commissioned by We Are Equals for International Women's Day, which sees 007 star Daniel Craig undergo a dramatic makeover as he puts himself in a woman's shoes.