The Bank of America’s online banking site suffered occasional problems Tuesday after threats on the internet that a cyber-attack would be launched on the bank and other US targets in protest at a film mocking Islam.

A message on pastebin.com claiming to be from ‘cyber fighters of Izz ad-din Al qassam’- a reference to the military wing of Hamas- declared that it would attack the Bank of America and the New York Stock Exchange as a first step in a campaign against “American Zionist Capitalists”.

The posting promised to continue aggressive actions until the “erasing of the nasty movie”, which although YouTube has blocked in volatile regions, remains available in other parts of the world.

The film in question, a privately funded short-movie, mocking the Prophet Mohammad, has ignited days of demonstrations.The uproar has left many dead across the Arab world, including Africa, Asia and some Western countries.

A Bank of America spokesman told Reuters that the website had suffered some problems but was available to customers.

But customers contacted by Reuters in Michigan, Ohio, Georgia and New York said they couldn’t access the site.

The threat to the New York Stock Exchange has seemingly not materialized as trading continued as normal.

Bill Pennington, chief strategy officer at WhiteHat Security, told the weekly magazine InformationWeek that the problems on the Bank of America website do not necessarily mean they’ve been hacked.

“It’s reasonable to suppose it could be a coincidence,” he said, citing the recent GoDaddy outage, which was an internal technical error for which hackers claimed responsibility.

But he did concede that the website’s problems could also be the result of hackers, saying that hacking was “pretty easy”.

He said that only the perpetrators and possibly the victims [the Bank of America] will ever really know what happened.

Pennington warned that businesses should expect more attacks, “It’s probably going to get worse before it gets better,” he said.