BANGKOK - Gunmen opened fire near several opposition protest sites in Bangkok Wednesday, stoking tensions in the capital as Thailand’s embattled prime minister flew to her political stronghold in the north.A dangerous new chapter appears to have been opened in a nearly four-month political crisis that has left 22 people dead and hundreds wounded, with almost daily reports of gunshots and grenade blasts in the capital recently - often targeting protesters.Police said unknown gunmen fired sporadically early Wednesday for around an hour in three areas of Bangkok where demonstrators are camped out alongside upscale shopping malls and luxury hotels. Nobody was wounded.“We don’t know which side fired the shots, but the aim of the gunmen is to intimidate,” deputy national police spokesman Anucha Romyanan told AFP.The spike in violence has been largely confined to areas close to the opposition rallies, which tourists have been urged to avoid, particularly after dark.But foreigners can still be seen wandering around several protest sites, which often resemble street markets and sit next to major hotels, shopping malls and Lumpini Park. Prime Minister Yingluck Shinawatra is under intense pressure to step down, with the protesters calling for an unelected “people’s council” to tackle what they see as corruption and a culture of money politics. Her supporters say they will not accept the removal of an elected government by the protesters, military or the courts, raising fears of a protracted standoff.Yingluck has been summoned by an anti-graft panel on Thursday to hear charges of neglect of duty in connection with a rice subsidy scheme that the opposition says is rife with corruption.If found guilty she could be removed from office and face a five-year ban from politics.Yingluck flew to the northern city of Chiang Rai on Wednesday to inspect government-backed projects, saying she might not attend the National Anti-Corruption Commission (NACC) hearing.“I have not yet made up my mind,” she told reporters when asked if she would face the panel.NACC commissioner Vicha Mahakhun said Yingluck’s lawyer had informed the panel that he would represent her at the hearing.“If she doesn’t show up we can send the documents by registered mail,” Vicha said.Officials denied the premier was on the run from protesters, who have vowed to pursue her wherever she goes and have besieged state buildings where she has held cabinet meetings since the occupation of her headquarters in December. “She is not avoiding the political situation in Bangkok,” said Transport Minister Chadchart Sittipunt. More than 700 people have been wounded in street violence since demonstrators took to the streets in late October seeking to curb the political dominance of Yingluck’s billionaire family.The opposition blames Yingluck’s followers for the violence, while government supporters accuse the demonstrators of trying to incite the military to step in.Four children were among those killed in two separate grenade and gun attacks on opposition rallies in Bangkok and eastern Thailand over the weekend, drawing widespread condemnation.Protesters have occupied several key intersections in the Thai capital, with guards - many wearing body armour - searching cars and pedestrians at roadblocks made from tyres and sandbags. It is the country’s deadliest political unrest since 2010, prompting warnings from the army chief that Thailand risks sinking into civil war unless the two sides pull back.Thailand has been scored by deep divisions since a bloodless coup by the military in 2006 ousted Yingluck’s elder brother, Thaksin Shinawatra, as prime minister.The latest political violence is the worst since more than 90 people died during protests by pro-Thaksin “Red Shirts” in 2010 that sparked street clashes and a bloody military crackdown.Yingluck swept to power in 2011 on a wave of support in the rural north and northeast, helped by the flagship rice policy which paid farmers up to 50 percent above market rates for their crop. But the scheme has left the kingdom with stockpiles of unsold rice after Thailand lost its rank as the world’s top rice exporter.A general election held on February 2 failed to calm the crisis after protesters obstructed the vote in many opposition strongholds. Election re-runs are due to be held on March 2 in five of the affected provinces.