The United States has imposed financial sanctions on Zimbabwe's spy chief, President Robert Mugabe's nephew and two companies the U.S. accuses of undermining democracy in Zimbabwe.

The U.S. Treasury Department Wednesday blacklisted Happyton Bonyongwe, head of Zimbabwe's Central Intelligence Organization, and Leo Mugabe, a member of Zimbabwe's parliament and Mr. Mugabe's nephew.

A statement says the U.S. financial system is now closed to those two, as well as two companies linked to President Mugabe's ruling ZANU-PF party. It says those companies, ZIDCO Holdings and Jongwe Printing and Publishing Company, are "owned or controlled" by key components of Mr. Mugabe's government that have already been designated.

A Treasury Department official, Adam Szubin, said the designations are part of an increased U.S. effort to pressure those aiding what he said was Mr. Mugabe's attempt to cripple Zimbabwe through violence, intimidation and other means.

Some information for this report provided by AP and Reuters.