Security measures have been beefed up in the city's diplomatic areas, as well as at different religious establishments, since yesterday.
Additional law enforcement agencies' members have been deployed to strengthen surveillance.
Police were seen frisking people and setting up check-posts at Gulshan-Banani-Baridhara areas.
Different clubs and embassies have been brought under the security blanket while hotel authorities have been asked to keep all details of their boarders.
The sudden initiative led to many people taking to social media to know the reasons.
The official reason for the additional vigilance was that it was for ensuring peaceful Independence Day celebrations on March 26, according to police officials.
Masudur Rahman, deputy commissioner (media) of Dhaka Metropolitan Police (DMP), said it was “nothing new.” Police usually did so during special days, he said.
Meanwhile, the DMP on its official news portal last night said they had issued no red alert fearing attacks in the city, despite different media outlets reporting such. There is no specific threat either, it said.
In the afternoon, however, several officials said the measures stemmed from threats of militant attacks on religious establishments.
Hayatul Islam Khan, deputy commissioner of Diplomatic Security Division at DMP, said he was asked to beef up security in the area, which would remain for the next two days.
Sources in the DMP's Counter Terrorism and Transnational Crime unit, said the arrangements were taken following information on possible attacks.
Police in Chattogram also beefed up security in key establishments and religious institutions. They raided different hotels yesterday and gathered information on the current boarders there.
Following heightened security, most diplomatic missions in Dhaka, including the ones of the United States and United Kingdom, issued security alert for their citizens living in the country.
“The US Embassy is looking into reports about the need for heightened vigilance in Dhaka,” said a security alert issued yesterday.
It added that all routine consular services would remain available.
The British High Commission in Dhaka issued an almost similar alert.