(Adds U.S. and UK comment on new charge against Suu Kyi)

* Military denies its action amounted to a coup

* Second charge filed against Aung San Suu Kyi

* Protesters block train service to south

* China dismisses rumours of help for military

Feb 16 (Reuters) - Myanmar's military junta promised onTuesday that there would be an election and it would hand overpower as police filed an additional charge against toppledformer leader Aung San Suu Kyi.

It also defended its Feb. 1 seizure of power, denying it wasa coup even as protesters took to the streets again in supportof Suu Kyi and other arrested leaders and China dismissed socialmedia rumours that it had helped with the military's action.

"Our objective is to hold an election and hand power to thewinning party," Brigadier General Zaw Min Tun, spokesman for theruling council, told the junta's first news conference sinceoverthrowing Suu Kyi's government.

The military has not given a date for a new election but hasimposed a state of emergency for one year. Zaw Min Tun said themilitary would not hold power for long.

"We guarantee... that the election will be held," he toldthe nearly two-hour news conference, which the militarybroadcast from the capital, Naypyitaw, live over Facebook, aplatform it has banned.

Asked about the detention of Nobel Peace Prize winner SuuKyi and the president, Zaw Min Tun dismissed the suggestion theywere in detention, saying they were in their homes for theirsecurity while the law took its course.

Suu Kyi, 75, spent nearly 15 years under house arrest forher efforts to end military rule.

She faces charges of illegally importing six walkie-talkieradios and is being held on remand until Wednesday. Her lawyersaid on Tuesday police had filed a second charge of violating aNatural Disaster Management Law.

The United States was "disturbed" by reports of theadditional criminal charge against Suu Kyi, State Departmentspokesman Ned Price said. Washington imposed new sanctions lastweek on the Myanmar military. No additional measures wereannounced on Tuesday.

British Prime Minister Boris Johnson also decried the newcriminal charge, saying it was "fabricated" by the military.

Zaw Min Tun said Myanmar's foreign policy would not change,the country remained open for business and deals would beupheld.

The military will be hoping its reassurances will dampen thecampaign of daily opposition to its rule and to the removal ofSuu Kyi and her government.

As well as the demonstrations in towns across the ethnicallydiverse country, a civil disobedience movement has broughtstrikes that are crippling many functions of government.

The unrest has revived memories of bloody outbreaks ofopposition to almost half a century of direct army rule thatended in 2011 when the military began a process of withdrawingfrom politics.

Police have opened fire several times, mostly with rubberbullets, to disperse protesters. A protester who was shot in thehead in Naypyitaw last week is not expected to survive.

Six people were wounded in the central town of Maungmya onTuesday when police fired rubber bullets to break up a protestover an arrested teacher, a witness said. An army statement saidprotesters had thrown stones at police, injuring some officers.

Zaw Min Tun said a policeman had died of injuries sustainedduring a protest in Mandalay on Monday.

He said the protesters were starting violence while thecampaign of civil disobedience amounted to the illegalintimidation of civil servants.

"We will wait patiently. After that, we will take actionaccording to the law," Zaw Min Tun said.

The army has given itself extensive search and detentionpowers and has made penal code amendments aimed at stiflingdissent with tough prison terms.

TRAIN BLOCKED

Protesters milled onto a sun-baked stretch of railway trackearlier in the day, waving placards in support of thedisobedience movement and blocking trains between the commercialcapital Yangon and the southern city of Mawlamyine.

"Release our leaders immediately," and "People's power, giveit back," the crowd chanted in live images broadcast by media.

Crowds gathered in Yangon, including at the central bank,where protesters called for staff to join the civil disobediencemovement. Buddhist monks also rallied against the coup in Yangonwhile hundreds marched through the west coast town of Thanked.

The army took power alleging that its complaints of fraud ina Nov. 8 general election were being ignored. Suu Kyi's NationalLeague for Democracy party had won a landslide in the election.

The electoral commission had dismissed the army'scomplaints.

The coup has prompted an angry response from Westerncountries.

But China has taken a softer approach, arguing stabilityshould be the priority in its neighbour, where it has closecontacts with the military. China did, however, join other U.N.Security Council members in calling for the release of Suu Kyi.

On Tuesday, Chinese Ambassador Chen Hai said the situationwas "absolutely not what China wants to see" and dismissedrumours of Chinese involvement in the coup as "completelynonsense".

Chen, in an interview with media posted on his embassy'sFacebook page, said Beijing maintained friendly relations withboth the army and the former government and had not been"informed in advance of the political change".(Additional reporting by Martin Petty in Bangkok; Writing byMatthew Tostevin and Robert Birsel; Editing by Mark Heinrich,Grant McCool and Rosalba O'Brien)