American victims of bombings and rocket attacks in Israel have sued Switzerland's biggest bank, UBS, for more than $500 million (SFr522 million).

The lawsuit, filed in New York, accuses the bank of helping fund the organisations behind the attacks through dealings with Iran.

It seeks damages for more than 50 United States citizens who were injured in Israel between 1997 and 2006 or for relatives of people killed.

US government reports say Hezbollah, Hamas and Palestinian Islamic Jihad groups financed by Iran since 1996 carried out the attacks.

The lawsuit alleges that UBS broke 1996 US laws prohibiting individuals and companies from engaging with state sponsors of terrorism. The legislation was designed to impede Iranian access to foreign capital.

"UBS knew full well that the cash dollars it was providing to a state-sponsor of terrorism such as Iran would be used to cause and facilitate terrorist attacks by Iranian-sponsored terrorist organizations," the lawsuit states.

"These organisations used Iranian money to commit their attacks," said the plaintiffs' lawyer, Nitsana Darshan-Leitner, who added that other banks could face legal proceedings if the case against UBS goes ahead.

UBS spokesman Serge Steiner said on Tuesday that the claims were "groundless" and that the lawsuit lacked any "legal basis".

In 2004, the US government fined the bank $100 million for transferring funds to Iran, Cuba and other states subject to US trade sanctions, and then trying to hide the transactions.

Two years ago, UBS said it had cut ties with all of its clients in Iran.

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