Witnesses said police in riot gears took positions around Zia's house barring party activists and visitors' entry into its premises at up market Gulshan area. (Agencies)
However, it was not clear if the 68-year-old former Prime Minister was kept under house arrest.
"We have been working for whatever we think required to maintain law and order and security of all," police commissioner Benajir Ahmed told reporters without elaboration.
But Zia's international affairs adviser Shamsher Mobin Chowdhury was quoted as saying in media reports that "since yesterday she has been under virtual house arrest" and alleged that it was part of a government move to foil the December 29 'march for democracy'.
Police officials, however, rejected the claim that Zia was detained and said they were ordered just to intensify the security of her residence and other party leaders.
No Bangladesh Nationalist Party (BNP) leader was available for reactions immediately.
Meanwhile, TV news channels reported that police detained BNP lawmaker Shammi Akhtar from in front of Zia's house late last night along with three other junior party leaders.
On December 24, Zia urged people to march towards Dhaka on December 29 from all over the country to "protect democracy" after the 18-party opposition alliance wrapped up their nearly month-long blockade, sparking widespread violence that claimed over 130 lives.
"This march will be historic, we have named it as 'march for democracy'...I urge all able bodied countrymen cutting across their affiliation, religion and class to join the rally on December 29," she had said.
BNP and its allies, including fundamentalist Jamaat-e- Islami, were boycotting the January 5 polls, while over half of the candidates in 300-seat Parliament were set to elected unopposed in the absence of rival candidates.
Zia asked the government to shelve the elections fearing "it could be last nail to the coffin of democracy" and accusing her arch-rival Prime Minister Sheikh Hasina of "killing democracy to consolidate power forever."
She also warned that her party would be forced to take "tougher actions" if elections were not postponed.
Witnesses said police in riot gears took positions around Zia's house barring party activists and visitors' entry into its premises at up market Gulshan area.