The popularity of U.S. treasury bonds as a safe investment target is growing amid the prolonged fiscal crisis in Europe.

The U.S. Treasury Department said the amount of U.S. state bonds held by foreign investors rose for the fifth consecutive month in May, up one percent month-on-month for a record five-point-26 trillion U.S. dollars.

China increased its holding of U.S. treasury bonds by zero-point-four percent to one-point-17 trillion dollars in May. Japan’s holding of U.S. state bonds also jumped one-point-four percent to one-point-one trillion dollars.

Experts attribute the rising demand for U.S. treasury bonds to Europe's worsening debt crisis.