In Hong Kong, police today vowed to pursue the ringleaders of anti-government protesters who besieged their headquarters and termed the demonstration illegal and irrational.<br />'' <br />'' Thousands of protesters blockaded the police headquarters on Friday and Saturday.<br />'' <br />'' The spark for the current wave of protests is the extradition bill, which the city's pro-Beijing leader Carrie Lam has postponed in the face of the huge public backlash.<br />'' <br />''Earlier this month millions had marched to oppose a proposed law that would have allowed extraditions to the Chinese mainland. <br />