Washington, April 23 (IANS): Bearing protest signs and many wearing lab coats, thousands of scientists from around the US began gathering here to express their objections to the cutbacks in scientific research proposed by President Donald Trump.

The protest on Saturday, dubbed the March for Science and coinciding with Earth Day, is being held in more than 500 cities around the world, but all eyes are on Washington, where the organisers hoped to attract as many as 75,000 people, Efe news reported.

The first scientists started arriving around 8.00 a.m. (local time) at the Washington Monument, looking toward the South Lawn of the White House, from where the protest was to set out at 2.00 p.m. down the National Mall and wind up in the streets around Congress.

While hundreds of people were lining up to join the march, dozens of volunteers were handing out signs with the official slogan of the protest: "Science, not Silence".

The organisers had insisted that the march should not be an anti-Trump event but rather a reminder of the important role science should play in society and in the political debate so that those in power can take sensible decisions based on "facts" and not "alternative facts".

Marchers held signs with slogans that read -- "Science should be shared not censored", "Rise up before the waters do", "Dinosaurs didn't believe in climate change either", "stop the war on facts", "Denial is not a policy", and "we're not just resistors, we are transformers", etc.

Other US cities like New York and Chicago also rolled out events in support of the March for Science.