White House demands probe into Trump's 'wire tapping' claims
The White House is demanding that a probe into Russian interference in last year's US presidential election also examine claims that former President Barack Obama had telephones at Trump Tower wire tapped.
White House officials said they want the congressional committees to determine whether "executive branch investigative powers" were abused in 2016 - a reference to President Donald Trump's claim of wire tapping in a series of tweets on Saturday.
Mr Trump has offered no evidence or details to support his claim, denied by Mr Obama's spokesman.
He made the allegations in a series of tweets claiming he "just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!"
Obama spokesman Kevin Lewis said a "cardinal rule" of the Obama administration was that no White House official ever interfered in any Justice Department investigations, which are supposed to be conducted free of political influence.
"As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any US citizen," Mr Lewis said, adding that "any suggestion otherwise is simply false".
Mr Trump compared the alleged activity to behaviour involving president Richard Nixon and the bugging of his political opponents.
"How low has President Obama gone to tapp (sic) my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy!" he tweeted.
Mr Trump said the wire tapping occurred in October. He ran the presidential transition largely out of Trump Tower in New York, where he also maintains a residence.
The call for an investigation came after c lashes broke out as hundreds of people gathered at sites around the US to join rallies backing Mr Trump.
From Colorado's state Capitol to New York and the Washington Monument, hundreds rallied for Mr Trump, waving "Deplorables for Trump" signs and carrying life-size cut outs of the president.
Police in Berkeley, California, said 10 people were arrested after Trump supporters and counter-protesters confronted each other during a rally that turned violent and left seven people injured.
A dagger, metal pipes, bats, pieces of lumber and bricks were confiscated, police said.
Six people protesting against a rally in St Paul, Minnesota, were arrested on felony riot charges after they lit fireworks inside the Minnesota State Capitol. About 400 people attended the event, and around 50 showed up to protest.
In Nashville, two people were arrested in clashes at the Tennessee Capitol. In Olympia, Washington, four demonstrators were arrested at a rally in support of Mr Trump, KOMO-TV reported.
Hundreds gathered in rallies at both ends of Pennsylvania to show support for Mr Trump.
In Augusta, Maine, more than 100 people turned out for an event that was supposed to last three hours, but ended early because of freezing temperatures.
In Indianapolis, about 30 Trump supporters rallied at the Indiana Statehouse to denounce what they see as unfair treatment of the Republican.
Trump supporters also turned out in Phoenix. Media outlets said several hundred people participated in the event on a lawn at the State Capitol.
In Texas, Austin police said about 300 people rallied in support of Mr Trump in a gathering outside the Capitol during rain.
Around 200 people rallied in Virginia Beach, Virginia, in a show of support for Mr Trump, and i n Lansing, Michigan, another 200 supporters rallied on one side of the state Capitol while 100 critics gathered on another side.