PETALING JAYA (THE STAR/ASIA NEWS NETWORK, REUTERS) - Malaysian politicians on Wednesday (May 9) say their mobile phones have been hacked and are being spammed by calls allegedly originating from the United States.

"BN leaders' handphones have been under technical attack since morning," said Barisan Nasional (BN) Strategic Communications director Datuk Seri Rahman Dahlan.

"Calls from overseas keep coming in every few seconds! To prevent us from communicating with our machinery," tweeted the Sepanggar parliamentary candidate.

"My phone seems to be under some form of spam attack this morning. Strange," Barisan Youth chief Khairy Jamaluddin, who is defending his Rembau parliamentary seat, tweeted on Wednesday morning (May 9), with a screenshot of these calls.

"Sorry to friends who couldn't reach me and please call my PA (personal assistant) Mr Beh for any urgency (sic)," he posted on Facebook, with accompanying screenshots.

Prime Minister Datuk Seri Najib Razak condemned the "spam calls" received by BN leaders, and said that many of the coalition's websites could not be accessed.

"I have ordered for immediate action to be taken," the prime minister said on Twitter.

Malaysian civil rights group Suaram said the spam calls, which have also affected civil society group leaders, was a "clear attempt to impede the work of human rights defenders and politicians at the critical juncture of voting day", Reuters reported.

Earlier, DAP secretary-general Lim Guan Eng said he and other party leaders received many calls from unknown numbers appearing like automated calls from overseas.

He said the "cyber warfare" on their cellphones was an attempt at preventing members from communicating with each other.

"This is a dirty tech attack on us, we have been paralysed. We cannot talk to anyone... they are trying to sabotage the electoral system to deny a PH win," he said.

He also urged the public and party members to practise caution whenever they receive calls appearing to be from them as it was attempt to hack their phones.

Lim said even his personal assistant Tan Khong Chong received a fake message which was said to be from him, claiming that he had changed his number.

The message read: "Since yesterday my phone has been hacked… all contacts hilang (lost)."

Lim said even the phones belonging to his father Lim Kit Siang and his press secretary Cheong Yin Fan were similarly affected.

"We will find out how widely it has affected our members. We will set up a parallel system with the existing system to ensure that we can continue to communicate," he said during a press conference at the Air Putih DAP centre.

While the complaints came from all sides, none of the political figures whose phones had been targeted specified who they suspected was behind the attack.

In a statement on Wednesday (May 9), the Malaysian Communication and Multimedia Commission (MCMC), the country's communications regulator, said that it has been receiving "numerous" complaints of ringing phones but the calls later dropped.

"This is being experienced repeatedly by all parties," said the MCMC. "Our initial investigation points to a technical cause of BOTS attack which is initiated anonymously from various sources with differing targets irrespective of the political parties.

"We seek that everyone stop this act immediately and refrain from further use of such technical attacks as it could jeopardise the telecommunication network causing inconvenience to the public and a security risk. For those getting such calls from unknown numbers please be advised to not answer it," the regulator added.

The MCMC also said the commission and their service providers will continue to investigate and stern action will be taken as provided by the law.

Azmin Ali, chief minister of the opposition-held state of Selangor, said he left his mobile phone in his car when he went out to vote as he was getting continuous calls and junk e-mails.

"This didn't happen (in the last election). I think the situation is different this time. They are desperate, so they are using all sorts of tactics to jam us. But at the end of the day, it's people's power," he told reporters after casting his vote.

Lembah Pantai PKR candidate Fahmi Fadhil also said his mobile phone was "flooded" with calls since 7am from unidentified numbers from the US.

He said he was receiving such calls every minute, making it impossible for him to receive genuine calls.

"My e-mail has also been inundated with phishing e-mails, probably to get information on my password to gain access to my Facebook or other social media accounts," he said.

Fahmi was speaking to reporters after casting his vote at SMK Seri Pantai in Jalan Kerinchi at 8.30am.

At 1.50pm, The Star reported that the Inspector-General of Police, Tan Sri Mohamad Fuzi Harun, was also affected by the spam calls.

"Earlier this morning, starting from 5am, even my own phone was affected. I believe this is to purposely disrupt the police's monitoring and communication during the voting period," he was quoted as saying after a walkabout at the SK Bangsar voting centre.

He added that he believes the spam calls were being made by "irresponsible parties".

Separately, BN has also claimed that its website has been hacked on polling day.

On its Twitter account, Barisan said its official website, www.barisannasional.org.my, could not be accessed.

Earlier, a check on the website revealed that an error appears, saying the page is "currently unavailable". The message also said the system administrator of the site should check the error log for details.

By 2pm, the site was back up.

IT security services company LGMS founder C.F. Fong said the website owner could easily check whether the site was hacked or overloaded by looking at its own server logs.

"The website or server owners will have all the details to be able to tell if they are really being hacked, or their site is just simply unable to cope with the Internet requests," he told The Star on Wednesday.

Fong urged Internet users not to speculate on whether the website was hacked, adding that if it was was under attack, there would be "logs and traces" of the incident.

Reuters news agency reported in April that automated accounts known as bots were flooding Twitter with tens of thousands of pro-government and anti-opposition messages, just weeks before the general election.