BANGKOK, Nov 24: Protesters calling for Thai Prime Minister Yingluck Shinawatra to step down rallied in the heart of Bangkok on Saturday, clashing with police in the first major demonstration against the government since it came to power last year.

Organisers had spoken of mobilising hundreds of thousands of supporters. But only around 10,000 turned up, and by dusk the leaders called the rally off.

Nevertheless, the tense gathering served as a reminder that the simmering political divisions unleashed after the nation's 2006 army coup have not gone away.

The coup toppled Yingluck's brother, Thaksin Shinawatra, triggering years of instability and mass-protests that have shaken Bangkok.

Saturday's rally was organised by a royalist group calling itself “Pitak Siam” — or “Protect Thailand.” Led by retired army Gen.

Boonlert Kaewprasit, the group accuses Yingluck's administration of corruption, ignoring insults to the monarchy and being a puppet of Thaksin.

Yingluck took the group's threats seriously and accused them of trying to topple her government, which came to power in mid-2011 after winning a landslide electoral victory. Concerned about possible violence, Yingluck deployed nearly 17,000 police and invoked a special security law to give them extra powers.

Although the rally site itself was peaceful, protesters on a nearby street tried to break through a concrete barricade guarded by thick lines of hundreds riot police with shields, at one point ramming a truck into it. Both demonstrators and police hurled tear gas canisters at each other.

Police spokesman Maj Gen Piya Utayo said five officers were injured in the skirmishes, two of them seriously.

He said 130 demonstrators were detained, some of them carrying knives and bullets. Local hospital staff said they treated 45 people and most had inhaled tear gas.

Speaking from the rally's central stage on Saturday, Boonlert vowed the demonstration would remain peaceful. But he said: “I promise that Pitak Siam will succeed in driving this government out.''

He then led the crowd in a chant: “Yingluck, get out! Yingluck, get out!''

The rally was held at Bangkok's Royal Plaza, a public space near Parliament that has been used by protesters in the past.

Police allowed protesters into the site, and two roads leading to it were open. But in an effort to control access, they blocked roads on another street leading to Royal Plaza.—AP