By Manuel Mogato and Randy Fabi

MANILA/JAKARTA (Reuters) - Hackers claiming links to international activist group Anonymous defaced dozens of websites belonging to Australian businesses and Philippine government agencies on Sunday.

A group calling itself Anonymous Indonesia posted on Twitter a list of more than 100 Australian sites it had hacked, saying the action was in response to reports of spying by Australia.

The websites, defaced with a message reading "Stop Spying on Indonesia", are mainly owned by small Australian businesses and seemed to have been chosen at random.

News of Australia's role in a U.S.-led surveillance network could damage relations with Indonesia, Australia's nearest Asian neighbour and an important strategic ally.

Reports that the Australian embassy in Jakarta was being used for spying prompted Indonesia to summon the Australian ambassador on Friday.

China demanded an explanation from the United States after the Sydney Morning Herald newspaper reported Australian embassies across Asia were part of the U.S. operation.

In a separate incident, a group calling itself Anonymous Philippines said on Facebook it had hacked Philippine government sites with a message seeking support for a protest demanding the abolition of "pork barrel funds" - money activists say is used for political patronage.

"We apologise for this inconvenience, but this is the easiest way we could convey our message to you, our dear brothers and sisters who are tired of this cruelty and this false democracy, tired of this government and the politicians who only think about themselves," read the message.

A scandal over lawmakers' misuse of public funds has become the biggest crisis of President Benigno Aquino's three-year rule, tainting his carefully crafted image as a corruption fighter and undermining his ability to push economic reforms.

National and local government agencies and the website of the Philippine embassy in Seoul were among those hacked.

Last week, an Internet video by someone claiming to be part of Anonymous threatened to bring down key infrastructure in Singapore to protest against new licensing rules imposed on websites there.

A blog section of the pro-government Straits Times newspaper was hacked on Friday morning and temporarily carried a statement complaining about how the paper had reported the hacking threat. The paper referred the matter to the police.

(Additional reporting by Rachel Armstrong in Singapore; Editing by Ron Popeski and Robin Pomeroy)