In a massive country-wide crack down, the caretaker government in Bangladesh has arrested at least 12,000 people using emergency powers prompting scores of political leaders to go underground in the past week, reports said on Saturday.Security forces have arrested a number of senior leaders of both the Awami League and the Bangladesh Nationalist Party in the southeastern port city of Chittagong. Over a dozen leaders of the student wings of Awami League and BNP have also been arrested in the past two days.Paramilitary Bangladesh Rifles and the coastguard have been put on high-alert to prevent criminals from fleeing the country. Security personnel from the Rapid Action Battalion were engaged in looking for Giasuddin Al Mamun, an influential business partner of former prime minister Khaleda Zia’s son Tarique Rahman, Prothom Alo newspaper said.The BNP has advised its leaders and activists to take cover to avert arrest, the Daily Star said. The report quoting an anonymous party source said the BNP might opt out of the election if the crackdown eventually turns unfavourable while the Awami League earlier said they would closely monitor the actions of the interim government.Meanwhile, both the Awami League and the BNP in a rare show of unity flayed Nobel prize winning economist Mohammad Yunus for saying last week that politicians were in politics only for money.