Anti-government protesters travel on a pick-up truck between different government institutions to protest in Bangkok February 24, 2014. REUTERS/Damir Sagolj

By Pairat Temphairojana and Amy Sawitta Lefevre

BANGKOK (Reuters) - Shots fired by unknown gunmen on Wednesday rattled parts of the Thai capital where anti-government protesters have set up camp for weeks, with small but occasionally deadly bombs and gunfire fast becoming the new norm in the city.

No one was wounded in the shootings in the central commercial area of Bangkok, although five people were killed in weekend violence in the city and the eastern province of Trat, four of them young children.

National security chief Paradorn Pattanathabutr said there had been no reported deaths or injuries in the incidents in the early hours of Wednesday.

"As for the perpetrators, we still don't know who they are," he told Reuters. "Recently we have been seeing more incidents like this happening more frequently ... It is noticeable that there are incidents like this every day."

The protesters, whose disruption of a general election this month left polarised Thailand in political paralysis, want to topple Prime Minister Yingluck Shinawatra and erase the influence of her brother, ousted premier Thaksin Shinawatra, seen by many as the real power in the country.

Occasional contact between the two sides, amid calls for an end to the violence, has so far led to nothing.

Bluesky TV, the protesters' station, showed demonstrators pushing against the wrought iron gates of the national police headquarters in Bangkok, demanding the proper investigation of more than 20 deaths since the beginning of the protests.

They did not get into the compound and dispersed in the early afternoon.

The protesters have vilified the police as lackeys of Thaksin, a former police officer who went on to build a telecoms empire.

"We want the police to do their job honestly and straightforwardly," said Anchalee Paireerak, a protest leader and former television news anchor. "We urge them to stop serving the Thaksin regime and join our movement."

The protesters want to set up an unelected "people's council" of the good and worthy to oversee vaguely defined political reforms, including a restructuring of the police force, before new elections are held.

ECONOMIC COSTS

Charges of negligence are to brought against Yingluck on Thursday by Thailand's anti-corruption agency relating to a rice subsidy scheme that paid farmers above-market prices and has proved financially ruinous.

Yingluck is in the northern city of Chiang Mai - her family's home town - and is unlikely to attend the hearing in person.

Some Yingluck supporters have said they would camp outside the agency's offices in Bangkok overnight to stop officials getting into work on Thursday.

The crisis flared up in November and the protesters have blocked several main intersections in the capital since mid-January. Although their numbers have dwindled, they are still managing to disrupt government business, forcing some agencies or ministries to close.

This has taken a toll on confidence and the economy.

Official figures on Tuesday showed a slump in trade in January.

Imports fell 15.5 percent from a year earlier, the biggest tumble since October 2009. Imports of computers and parts were down 19 percent, vehicle parts were off 31.8 percent and consumer goods down 5.3 percent. Exports dropped 2 percent.

A boom in the housing market may be coming to an end. The number of new housing units hit a record high in 2013 but developers are braced for a contraction this year because of the political crisis.

Land & Houses Pcl , the country's largest home builder, saw a 50 percent fall in December presales - the value of bookings for property units - and Kasikornbank said its housing loans were 50 percent below target in January.

(Additional reporting by Aukkarapon Niyomyat and Khettiya Jittapong; Writing by Nick Macfie; Editing by Alan Raybould and Robert Birsel)