|Commuters walk past bouquet of flowers, placed on fence at the King's Cross Underground Station, hit by explosion Thursday|
Flags flew at half-mast in Sydney to honor the dead in Thursday's bombings in the British capital - where hundreds of thousands of Australians live.
Australian Foreign Minister Alexander Downer said his government is fully behind the British people.
"Our sympathy goes out to them but also we join Tony Blair and his government and the people of Britain in their determination to be strong and to stand up to terrorists and not in any way to weaken in the face of this appalling act," he said.
Immediately after the attack, the government set up a hotline for Australians living in Britain.
Australia is no stranger to terrorism: dozens of its citizens died in 2002 Bali bombings. There has been no report of Australian fatalities in London.
On Thursday, authorities stepped up security in major transportation across Australia, a key ally of Britain and the United States in the war against terrorism.
In Hong Kong, another former British colony, Chief Executive Donald Tsang expressed shock and ordered higher security measures in the wake of the bombings of London's buses and underground railway. Hong Kong is due to host a conference of the World Trade Organization in December, and is expecting large-scale demonstrations.
The predominantly Muslim countries of Indonesia and Pakistan, which have also suffered terrorist attacks in the past, condemned the attacks and expressed sympathy to the British people.
Most major countries in Asia, in fact, have endured terrorist attacks in one form or another, including China, South Korea and Japan.
Japanese Foreign Minister Nobutaka Machimura described the London attacks as a "heinous" act of terrorism.
Security has been heightened in Tokyo's train systems - which suffered a deadly attack with sarin nerve gas in 1995.
Neighboring South Korea also tightened security in airports, government offices and other public facilities.
Beijing also condemned the attacks and promised to continue to work with the international community to fight terrorism.