NEW YORK – Larry Fink said last month he would thrust climate change concerns to the center of BlackRock’s investment strategy. That didn’t stop activists from storming its Paris office on Monday.

Protesters barricaded the premises, sprayed red paint on the floors and covered walls with graffiti before leaving. The firm has seen also protests in other cities over the past few years, including its New York headquarters and London. Demonstrators have trailed CEO Fink to events and speaking engagements.

The world’s largest asset manager and its competitors are under increasing pressure to tackle environmental and social concerns. Fink’s pledge to change BlackRock’s approach came after months of controversy that focused on its fossil-fuel and private-prison holdings, and highlighted the challenge facing investment firms that want the best returns while also being perceived as good actors.

In the wake of his January announcement, Fink gave two executives new sustainability roles, and the firm began cutting its stake in the biggest US coal miner. This month, it rapped Siemens on the knuckles for its handling of a controversial rail contract for an Australian coal mine, which has come under criticism from environmental activists.

While those changes are the first steps under Fink’s new strategy, Monday’s action shows how far it will need to go if it wants to satisfy its harshest critics. During the occupation of the Paris office “BlackRock assassins” and “I want to live” could be read on walls and windows. There were also anarchist logos. One activist interviewed on a live feed posted online said the blockade was also a protest against the French state’s inaction on climate issues.

“We condemn in the strongest terms the violent intrusion and acts of vandalism at our offices this morning,” said BlackRock spokesman Ed Sweeney. “These acts, as well as the attempts to intimidate our employees over the past several weeks, are unacceptable and will not be tolerated.”

Youth For Climate France said in a statement that it targeted BlackRock for its investments in companies that damage the environment, listing Vinci, Total, BNP Paribas and Societe Generale among them.

“BlackRock, because of its sense of fiduciary duty, is going to move fairly gradually,” said Cait Lamberton, a professor of marketing at The Wharton School of the University of Pennsylvania. “That’s not going to be satisfying to activists, and we’ll have to wait and see if that will be satisfying to the planet.”

It would be difficult for BlackRock to rapidly overhaul all of its portfolios, even if it wanted to. About two-thirds of its more than $7-trillion in assets are in products that track indexes -- and are expected to hold the component stocks in those gauges -- limiting their freedom to ditch businesses.

Fink has said there are ways around that problem in the longer term, for example doubling its offering of sustainability-focused exchange-traded funds to 150.

In the meantime, the fund firm is exiting thermal coal producers in its nearly $2-trillion of actively managed funds. The company had about 4.87-million shares of Peabody Energy, amounting to a 5% stake, as of December 31, according to a regulatory filing Friday. That’s down 14% from the end of January 2019, making it the miner’s sixth-largest holder.