* Thai army chief calls for calm, orders troops to stay neutral
* Pro-govt supporters to stage rival rally
* Coup rumours mount in Bangkok (Adds details on shooting, army chief comment)
By Amy Sawitta Lefevre
BANGKOK, Jan 11 (Reuters) - Seven people were wounded after gunmen on motorcycles opened fire on anti-government protesters in Bangkok early on Saturday, heightening fears of worsening violence when protesters attempt to "shut down" the capital next week in a bid to overthrow the government.
The gunmen opened fire on protesters in central Bangkok at around 2 a.m, and at least one other attack took place nearby, police said.
"Unidentified assailants opened fire in the early hours of this morning ... at an intersection near the Khao San Road tourist area. Altogether seven people were injured, most of them anti-government protesters," said national police chief Adul Saengsingkaew.
The attack came just hours after clashes between government supporters and protesters outside Bangkok that left at least six people hurt.
The incidents occurred as authorities draw up plans to deploy more than 14,000 troops and police on Bangkok's streets from Monday. From then protesters led by former opposition politician Suthep Thaugsuban aim to paralyse the city for between 15 and 20 days.
The turmoil is the latest episode in an eight-year conflict that pits Bangkok's middle class and royalist establishment against the mostly poorer, rural supporters of Prime Minister Yingluck Shinawatra and her brother, former premier Thaksin Shinawatra, who was overthrown in a military coup in 2006.
The protesters accuse the Shinawatra family of corruption and nepotism. Yingluck called a snap election for Feb. 2, but this failed to placate protesters, who want her government to resign to make way for an unelected people's council to oversee political reform.
Many Thais believe the military will soon step in to break the political deadlock, especially if the protests turn even more violent, and rumours of an impending coup have intensified.
The army has staged or attempted 18 coups in 81 years, but it has tried to remain neutral this time.
The country's top general called for calm ahead of the city-wide protests and ordered troops to stay neutral in the crisis. "All sides must act in a way that causes the least disturbance to Bangkok residents," said army chief Prayuth Chan-ocha.
Eight people, including two officers, have been killed and scores injured in violence between protesters, police and government supporters in recent weeks.
One of those injured in the shooting early on Saturday remains in a critical condition, according to the Erawan Medical Center which monitors Bangkok hospitals.
KEY SITES PROTECTED
Fears of more clashes between rival factions escalated after pro-government "red shirts" announced they would stage their own march on Monday in provinces neighbouring Bangkok.
At a celebration to mark national Children's Day on Saturday, army chief Prayuth Chan-ocha said he feared an escalation in violence next week.
"I want to tell all sides they must not clash with each other ... we are all Thais and can live together despite our differences," said Prayuth.
Amid fears of escalating trouble, security forces have been deployed across the capital to protect key sites including the prime minister's office, Bangkok's main airport and the city's water and electricity authorities.
Bangkok's traffic police and the city's emergency medical services say they expect some disruption to services next week.
"As the protests will block key roads this will affect transportation of patients to and from hospital ... we have prepared backup measures including helicopters to transport the injured," said traffic police commander Jirasan Kaewsaenga-ek.
Paralysing Bangkok is the latest bid in a two-month attempt by protesters to topple Yingluck.
Protesters plan to block seven main intersections in Bangkok, causing gridlock in a city clogged with traffic at the best of times, and say they could block other areas as part of their prolonged siege of the city. (Reporting by Amy Sawitta Lefevre; Editing by Michael Perry and Jeremy Laurence)