Google expands campaign to help European refugees with $5.5 million pledge to match donations

Google's charitable arm is pledging to donate an additional $5.5 million to groups trying to help the thousands of refugees pouring into Europe.

The commitment announced Tuesday by expands upon a $1.1 million donation to several humanitarian relief funds earlier this month.

Google is trying to spur more people to contribute to the cause with this campaign. The Mountain View, California, company is matching up to $5.5 million in donations made by individuals through .

Donors can give their money to one of four groups: The International Rescue Committee, Doctors Without Borders, U.N. High Commission for Refugees, or Save The Children.

Google ended June with $70 billion in cash.