New York: American victims of bombings and rocket attacks in Israel have sued Swiss bank UBS AG for more than $US500 million ($NZ656.42 million), accusing the bank of helping fund the militants behind the attacks through dealings with Iran.

The lawsuit seeks damages from Switzerland's largest bank for more than 50 US citizens hurt or relatives of those killed in bombings in Israel between 1997 and 2006 that it said were carried out by militant groups Hizbollah, Hamas and the Palestinian Islamic Jihad.

UBS AG broke several 1996 US laws that prohibit persons and companies from engaging with state sponsors of terrorism and were designed to impede Iran's access to foreign capital, the suit said.

The lawsuit, filed on Friday in federal court in New York, cited US government reports that conclude Iran has been the main sponsor of Hizbollah and Hamas since 1996, including providing tens of millions of cash annually. The US government considers Hamas and Hizbollah terrorist organisations.

"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 organisations such as Hamas, Hizbollah and PIJ," the lawsuit said.

UBS spokeswoman Rohini Pragasam declined to comment on the suit.

In 2004, the United States fined UBS $US100 million for transferring dollars to Iran, Cuba and other nations subject to US trade sanctions and then trying to hide the transactions.

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

Because of US sanctions on financial dealings with Hamas and Hizbollah, Iran's financial backing "substantially increased" the militants' ability to carry out bombings, the lawsuit said.

The people named in the suit include US citizens in New York, California and Oregon who are seeking damages for wrongful death, physical and psychological injuries, assault and emotional distress. Several also live in Israel.

The plaintiffs were victims of attacks including a July 30, 1997 Hamas suicide bombing of an outdoor market in Jerusalem that killed 15 people and wounded 168, the lawsuit said.

The Hizbollah attacks were part of thousands launched at civilian targets in Northern Israel during July 2006, it said.