This is odd: Reports of gunfire and tanks in Beijing. Several updates. UPDATE December 2013.

After the ouster of Bo Xilai last week, now this.  Bo is a corruptocrat in some stories or a reformer and old-style Communist patriot in others. Excerpt from Washington Times:   (See also this new story that Bo's wife's is held responsible for the death of a British businessman).  (See UPDATE December 11 2013 at foot of this story.)

U.S. intelligence agencies monitoring China’s Internet say that from March 14 to Wednesday bloggers circulated alarming reports of tanks entering Beijing and shots being fired in the city as part of what is said to have been a high-level political battle among party leaders - and even a possible military coup.   The Internet discussions included photos posted online of tanks and other military vehicles moving around Beijing.  The reports followed the ouster last week of senior Politburo member and Chongqing Party Secretary Bo Xilai, who was linked to corruption, but who is said to remain close to China’s increasingly nationalistic military.

The Washington Times reported earlier on Bo's ouster:

As big-city politician Bo Xilai rose to nationwide prominence with an anti-mafia crusade and mass sing-alongs of communist anthems, many of China‘s leaders trekked to his metropolis approvingly. Not President Hu Jintao.Mr. Hu’s conspicuous absence from Chongqing, one of China‘s biggest cities, was telling. The charisma and self-promotion that made Mr. Bo popular with many Chinese at times alienated his political peers.

Walter Russell Mead weighed in with background just after Bo's ouster:

Maoist websites have been shut down, ostensibly for “maintenance.” A public park in Chongqing where retirees sang and twirled to patriotic anthems while waving red flags posted a notice saying the music was now banned because it disturbed the neighborhood.

Update from the Daily Mail:  Nervous leaders in China have blocked all internet reports of an alleged attempted coup.  Article has some more background on Bo Xilai, good pictures and information about the Hong Kong election. Beijing has decided to support a different candidate. (Update: election results) Universal suffrage due in HK in 2012 at end of Leung's term.)

Update from Walter Russell Mead:   Bo's "Smash Black" Under Heavy Scrutiny"

"The portrait Chinese leaders had hoped to paint to the outside world of a smooth and seamless transfer of power is instead morphing into a general picture of lawlessness, corruption and terror that has some, including Wen, openly referencing the Cultural Revolution."

Update:  People arrested, websites shut down in China for spreading this rumor, or is it "rumor". 
And another update April 11th.  Bo Xilai Suspended From Politburo; Wife Arrested For Murder.
And April 26th: "Bo ran an extensive wiretapping operation that included top Communist Party officials".

Zhou Yongkang

UPDATE December 11 2013.  There may have been a coup attempt by Zhou in March 2012 and Bo Xilai may have been trying to raise a private army in cooperation with Zhou.  The gunfire in earlier stories is located now at Zhongnanhai, the Communist Party leadership compound in Beijing.