NEW DELHI — The army-backed caretaker government in Bangladesh that has netted hundreds of politicians and businesspeople in a yearlong anticorruption drive has now rounded up nearly 12,000 people in what it calls a crusade against crime.

Political parties have denounced the roundup, carried out in recent days, as a ploy to clamp down on political activity as Bangladesh prepares for national elections in December. The police chief, Nur Mohammad, told reporters this week in the capital, Dhaka, that the anticrime drive was started to guard against “deteriorating” law and order and to ensure a peaceful campaign season, not to harass politicians. By Wednesday evening, the police said more than 11,700 people were detained. The police said nearly half of those had pending arrest warrants.

The crackdown began after the two major parties, the Awami League and the Bangladesh Nationalist Party, rejected talks with the government until their leaders were released from jail. Sheik Hasina Wazed, of the Awami League, and Khaleda Zia, of the Bangladesh Nationalist Party, both former prime ministers and each other’s fiercest foes, are in jail on charges of corruption.

The Awami League geared up for a signature-gathering campaign this week and announced that it would encircle the makeshift jail where its leader was housed.

“Free and fair elections are not possible under the present environment,” Sajeeb Wazed, the son of the Awami League leader, said in a statement. “These arrests are also a direct attempt at manipulating who gets to campaign for these elections, and therefore these elections are going to be a farce.”

The army-backed administration took over Bangladesh, a Muslim-majority nation of 150 million people, in January 2007 after months of violent clashes between the rival political parties, forcing the cancellation of national elections scheduled for later that month. The government promised an anticorruption drive. Since then, about two dozen politicians and their associates have been convicted.

Human rights groups have criticized the government, accusing it of arbitrary arrests and torture.

Political demonstrations are banned under the emergency rule. However, since January 2007, the rules have been relaxed somewhat, and indoor meetings are now allowed.

Julfikar Ali Manik contributed reporting from Dhaka, Bangladesh.