PRECIOUS-Gold pushes back towards two-year high, silver crosses $21/oz

* Concerns over Brexit vote keeps traders on edge
    * Silver jumps 7 pct, gold 1 pct before paring gains
    * U.S. markets closed for Independence Day holiday
    * GRAPHIC-2016 asset returns:

 (Updates prices)
    By Jan Harvey
    LONDON, July 4 (Reuters) - Gold rose on Monday as political
uncertainty after Britain's vote to leave the European Union
supported prices that had been propelled towards last week's
two-year high by an overnight burst of short-covering activity
in China.
    The precious metal reached a peak of $1,357.60 an ounce
overnight, less than $1 below last month's high, before easing
back below $1,350 an ounce. 
    Silver benefited from a surge of buying in China, rising
more than 7 percent at one point and breaking above $21 an ounce
for the first time in two years. The metal has also benefited
from strong technical signals. 
    Spot gold was up 0.7 percent at $1,350.87 an ounce by
1520 GMT, while U.S. gold futures for August delivery
gained 1.1 percent to $1,353.70. 
    "The Brexit vote caused uncertainty and most people don't
like that," Commerzbank analyst Carsten Fritsch told the Reuters
Global Gold Forum on Monday. "Uncertainty leads to volatility in
financial markets and to a rush into safe havens such as bonds
and gold."
    A post-Brexit recovery across European markets stalled on
Monday, with major share indexes mixed. 
    Holdings in the world's largest gold-backed exchange-traded
fund, SPDR Gold Shares, rose by 3.9 tonnes to 953.91
tonnes on Friday, the highest since July 2013. In the first six
months of the year its holdings rose by 308 tonnes, its biggest
half-yearly increase in seven years. 
    The U.S. markets are closed on Monday for the Independence
Day holiday.
    Silver was up 2.9 percent at $20.30 an ounce,
benefiting from a perception that it offers good value compared
with gold. 
    The gold/silver ratio, which measures the number of silver
ounces needed to buy an ounce of gold, fell to a two-year low on
Monday as silver extended gains after its biggest weekly rise in
nearly three years.
    The Shanghai Exchange Futures went limit up overnight, with
onshore players having covered short positions aggressively in
the past few days, especially on Monday, one analyst with an
international investment bank said.
    "There is a little bit of a two-way battle going on in
silver with a number of players going short in China," the
analyst said.
    Hedge funds and money managers raised their bullish
positions in COMEX gold and silver contracts to record highs in
the week to June 28. 
    Platinum was up 0.1 percent at $1,059.75 an ounce,
while palladium rose 1.5 percent to $613.

 (Additional reporting by Vijaykumar Vedala in Bengaluru;
Editing by William Hardy and David Goodman)