Barclays does not invest in companies that supply weapons used by Israel in Gaza, the British bank said on Wednesday, after one of its branches in London's financial district was targeted by pro-Palestinian activists.

The bank has also faced criticism for providing financial services to defence firms that produce equipment used by the Israeli Defence Force.

Besides urging customers to boycott the bank, demonstrators have expanded protests to include defacing buildings and branches, using red paint to symbolise the bloodshed in Gaza.

Barclays' branch in Moorgate, central London, was the latest to be hit on May 1, traditionally a day of activism across many countries.

"We have been asked why we invest in nine defence companies supplying Israel, but this mistakes what we do," the lender said on its website.

"We trade in shares of listed companies in response to client instruction or demand and that may result in us holding shares. We are not making investments for Barclays and Barclays is not a 'shareholder' or 'investor' in that sense in relation to these companies," it said.

Barclays, which hosts its 2024 shareholder meeting on May 9, said its role as a bank was to provide financial services to defence companies, including U.S., UK and European ones that supply products to NATO and other allies.

The bank said it would "continue to monitor developments in Gaza closely", in view of the civilian death toll and targeting of aid workers in the region.

New York City police arrested dozens of pro-Palestinian demonstrators holed-up in an academic building on Columbia University campus late on Tuesday. Similar clashes between activists and counter-protesters were also seen on Wednesday at the University of California in Los Angeles (UCLA).

(Reporting by Sinead Cruise Editing by Mark Potter)