Swedish climate activist Greta Thunberg detained by Dutch police

Thunberg and other protesters of the Extinction Rebellion environmental group were seen sitting in a waiting bus, while police were continuing to make arrests, an AFP correspondent said.

Thunberg earlier joined several hundred protesters as they walked from the Dutch city centre to a field next to the A12 arterial highway leading out of the city.

The highway was the scene of previous protests by Extinction Rebellion with activists closing it off from traffic before police deployed water guns and made arrests.

READ ALSO: Greta Thunberg blocks entrance to Swedish parliament in climate protest

But on Saturday dozens of police officers, including some on horseback, blocked the group from entering the highway, warning that "violence could be used" should the marchers try to get onto the road.

Carrying XR flags and placards saying "Stop fuel subsidies now!" and "The planet is dying!", protesters were then locked in a tense standoff with police who formed a wall of law enforcement.

Some protesters then found another route and blocked a main road close to the highway -- which leads from the seaside city of The Hague to the central city of Utrecht.

Thunberg, dressed in a grey top, black trousers and blue shoes, joined the group at the start and was chanting songs with the group as they initially came to an abrupt stop.

"It's important to demonstrate today because we are living in a state of planetary emergency," Thunberg told AFP as police blocked marchers.

"We must do everything to avoid that crisis and to save human lives," she said.

At least one protester was arrested earlier and dragged away to a waiting police van, an AFP correspondent saw.

Asked whether she was concerned about police action and arrest, Thunberg said: "Why should I be?"

Activists said that despite majority backing by the Dutch parliament as well as broad popular support to slash fossil fuel subsidies, "the plans will not be implemented before 2030, or even 2035".

"Meanwhile the ecological crisis continues to rage and the country's outgoing cabinet pretends that we have all the time in the world, while the crisis is now," XR said in a statement posted on X, formerly Twitter.

The protest, added XR, was part of a plan to pressure the Dutch government ahead of another planned debate about fossil subsidies in June.

Thunberg in March blockaded the main entrance to the Swedish parliament, alongside a number of other climate activists, criticising the government for "not treating the climate crisis like a crisis at all."

The March blockade came just ahead of the fifth anniversary of the founding of her Fridays for Future global youth climate protest that drew over a million participants.

The activists sat on the steps of Sweden's parliament holding a banner reading "Climate Justice Now", as Thunberg criticised governments worldwide for inaction on the climate crisis.