International Women's Day (IWD) is being celebrated throughout the world, with this year's theme titled: "A promise is a promise: Time for action to end violence against women".

IWD has been observed since the early 1900s and was established by Socialist International, in their meeting in Copenhagen in 1910. The next year, the first International Women's Day was observed in several countries, including Austria, Demark, Switzerland Germany, according to the International Women's Day Web site.

In 1977, the UN General Assembly adopted a resolution proclaiming a United Nations Day for Women's Rights. The United States allotted the whole month of March as Women's History Month. Countries like China (for women only), Cuba, Belarus, Cambodia, Afganistan, Ukraine have declared Women's Day a national holiday.

UN General Secretary Ban Ki-moon released a statement on IWD, pointing to recent crimes against women all over the world and to urging all of humankind to "ask ourselves how to usher in a better future".

An excerpt from the statement reads:

"One young woman was gang-raped to death. Another committed suicide out of a sense of shame that should have attached to the perpetrators. Young teens were shot at close range for daring to seek an education. These atrocities, which rightly sparked global outrage, were part of a much larger problem that pervades virtually every society and every realm of life."

"This year on International Women's Day, we convert our outrage into action. We declare that we will prosecute crimes against women - and never allow women to be subjected to punishments for the abuses they have suffered. We renew our pledge to combat this global health menace wherever it may lurk - in homes and businesses, in war zones and placid countries, and in the minds of people who allow violence to continue."

Celebrities also joined in to celebrate the day and share their thoughts via Twitter.

"@oliviawilde Happy International Women's Day! Here's to the intelligence, resilience, and strength of women everywhere."

"@katewalsh woot RT @boyfriend: Happy International Women's Day! Hope you're spending it with your Billionaire @boyfriend"

"@Fergie Happy International Women's Day to all of my amazing, talented, strong sisters around the world!!!"

"@QueenRania Happy International Women's Day! Let us celebrate how far we have come and remember how much more we still have to offer #IWD"

"@lspraggan Happy International Women's Day. Just seen @BobbiBrown supporting #Dressforsucess with their #PrettyPowerful, nice!"

"@cesc4official Good morning to all but specially to all women that today is your day! Happy international women's day! #8thmarch #happy #friday"

"@TheRealLukevans Happy International Women's day! You are all truly phenomenal. Especially my Mam. ;-)"

"@JessicaCapshaw Happy International Women's Day! What woman or women are you most inspired by? Let's hear some shout outs for the ladies..."

"@MrSilverScott Happy International Women's Day! You're among my favorite people :)"

"@ginnygoodwin Happy International Women's Day! (I'm the luckiest lady alive... no offense.) @FaustinoDiBauda"

In the mean time, IBTimes UK invites you to photographs showing women across the world and in different professions and walks of life...