The United States issued Friday an emergency message to its nationals in the Philippines, urging citizens to exercise caution, following an attack at a casino in the capital.
"Local media reports gunfire and explosions at Resorts World Manila near the Manila International Airport. Exercise caution and review your personal security plans, remain aware of your surroundings, including local events, and monitor local news stations for updates," the US said in its emergency message.
"Heed any instructions given by local authorities," it added.
At least 30 bodies were found in at least two floors of the casino complex, following an attack by a supposedly lone heavily-armed suspect, who later committed suicide.
The still unidentified gunman fired shots inside Resorts World Manila, promoting a lockdown at the casino complex near Manila's main airport.
"Our assessment is he burned himself. He committed suicide," Oscar Albayalde, chief of the Manila police office, said in a radio interview.
The gunman burst into the casino, fired shots and set gaming tables alight in Resorts World Manila early on Friday, sowing panic in a country on high alert after martial law was declared in the south, but police said the motive was likely robbery.
Earlier, the Australian government also advised its citizens to exercise heightened caution
In its advisory, the Australian government cited reports of "a major security incident" at the Resorts World Hotel in Manila, near the Ninoy Aquino International Airport.
"Avoid the area and follow the advice of local authorities. Some flights have been redirected from Ninoy Aquino International Airport, contact your airline or tour provider for latest information on flight disruptions," it said.
"The deterioration in security in Mindanao has resulted in a more volatile security environment in the Philippines. Travellers are reminded of the high threat of terrorist attack in the Philippines, including Manila. Exercise heightened caution at this time. Be vigilant about your surrounds. Monitor the media for information that may impact on your security."