DHAKA - Two demonstrators were killed and more than 20 police injured in Bangladesh on Monday as officers fought to control a crowd of 10,000 people protesting over the disappearance of opposition leader Ilias Ali. Police said mobs armed with sticks and stones set fire to a local council building and attacked a police station in Sylhet city, home to Ali, a prominent Bangladesh Nationalist Party (BNP) figure who has been missing for six days."There were more than 10,000 protesters. They attacked policemen and tried to besiege a police station. We fired rubber bullets and tear-gas shells to disperse them," Shakhawat Hossain, police chief of Sylhet, told AFP.He added that a 25-year-old man was killed and more than 20 police officers were injured, four of them seriously. Abul Kalam Azad, a doctor at Sylhet's Osmani Medical College Hospital, said police also brought in the dead body of a 22-year-old protester.Local media said at least 100 people had been hurt in the violence, and reported that police had used live rounds to break up the protests. Rights groups have blamed Bangladeshi security agencies for the disappearance of dozens of opposition activists over the past two years, alleging the victims have been abducted on government orders. Police found Ali's car abandoned in an upmarket district of the capital Dhaka on Tuesday night. His driver is also missing. Ali, a regional head of the BNP, is the highest profile opposition politician to have "disappeared" since Prime Minister Sheikh Hasina's Awami League party took power in January 2009.The BNP has accused the elite Rapid Action Battalion (RAB) of abducting Ali, an allegation that the force and the government have rejected.Sylhet, 120 miles northeast of Dhaka, also saw brief clashes on Sunday, the first day of a national strike called by the BNP and its allies in protest at Ali's unexplained disappearance.In Dhaka, the streets were empty on Monday and businesses and schools were closed for the second day, while thousands of policemen were deployed to prevent violence. Two small bombs exploded in the city on Sunday, but no one was injured.The families of Premier Hasina and Khaleda Zia, head of the BNP, have competed for power for decades in Bangladesh with the personal rivalry between the two women often triggering street clashes between their parties. Violent protests in 2006 led to a suspension of democratic rule with a military-backed interim administration in control until Hasina won elections at the end of 2008. Both Hasina and Zia were detained for a year as part of an anti-corruption crackdown launched by the caretaker government. The current Awami League government has fallen in popularity in recent months due to soaring food prices, a cut in energy subsidies and a series of graft allegations.Anger has also been fuelled by the prime minister last year scrapping a system designed to oversee elections in a neutral manner. The BNP-led opposition alliance has called for the national strike to continue for a third day on Tuesday. Bangladesh, which has enjoyed strong economic growth in recent years but remains a deeply impoverished nation, is due to next hold elections by early 2014.