Foreign Minister Julie Bishop has been in contact with UK High Commissioner Alexander Downer, a Department of Foreign Affairs and Trade spokeswoman said.
"The Australian High Commission in London is making urgent inquiries to determine whether any Australians have been affected by an explosion aboard a commuter train at Parsons Green Station, London," she told AAP in a statement.
Armed police rushed to the underground station on Friday, with local media reporting there had been an explosion on a packed morning rush-hour commuter train.
British police said the blast was being treated as terrorism and a number of people had suffered injuries.
