Angry demonstrators in Kenya have marched to parliament to protest about a huge bonus MPs have voted to award themselves.Lawmakers in Kenya are among the highest paid MPs in Africa, receiving a salary of about $10,000 (£6,200) a month.The bonus of more than $105,000 each is to be paid when parliament breaks up ahead of elections due in March 2013.Analysts says tax increases are likely in order to foot the $23m bill.'Thief'The BBC's Frenny Jowi in the capital, Nairobi, says the revelation about the send-off bonus for the 222 MPs has angered many people, coming as it does after strikes in the public sector.It was passed late on Thursday night as part of a last-minute amendment to the Finance Act, she says.In September all schools were closed for three weeks and public hospitals only took emergencies as demands were made for better pay and working conditions.According to the AFP news agency, someone earning the minimum wage in Kenya would have to work for 61 years to earn the equivalent of the MPs' bonus.Our reporter says a large crowd stopped traffic on the main road outside President Mwai Kibaki's office in Nairobi.They then marched towards parliament and have camped outside, chanting "mwizi", which means thief in KiSwahili, when any MP drives by.The change to the Finance Act still needs to be signed into law by Mr Kibaki - who stands down as president next year after two terms in office.