Sri Lanka issued the ban as part of emergency measures enacted in the wake of the Easter Sunday suicide attacks. There are fears the step could fan tensions between religious groups in the Buddhist-majority country.
Women in Sri Lanka will no longer be able to cover their faces under new emergency regulations that came into force on Monday.
Authorities say the ban on all types of face coverings will help police easily identify people as they race to find suspects linked to a series of suicide attacks that killed more than 250 people on Easter Sunday.
"It is a presidential order to ban any dress covering faces with immediate effect," Dharmasri Bandara Ekanayake, a spokesman for President Maithripala Sirisena, told the Reuters news agency.
Dozens of people have been arrested over alleged links to the bombings, which targeted churches and luxury hotels. But local officials warn that there are still militants at large who could be planning another wave of attacks.
More than a week after the bombings, the island nation of 21 million remains on edge and under tight security. Thousands of soldiers have been deployed across the country to carry out searches and guard religious buildings, state offices and public places. Nighttime curfews are still in place in some areas.
The new face-veil ban does not refer specifically to Muslim female garb; it applies mainly to clothing such as niqabs and burqas.
Muslims make up about 9.7% of Sri Lanka's majority Buddhist population. Only a small number of Muslim women there fully hide their faces.
The All Ceylon Jamiyyathul Ulama (ACJU), the top body of Islamic scholars in Sri Lanka, said they backed a short-term face-covering ban on security grounds. But the group also voiced concerns that attempts to legislate against burqas, or prolong the ban, could fuel tensions in the religiously diverse nation.
"We have given guidance to Muslim women to not to cover their faces in this emergency situation," the ACJU's Farhan Faris said.
"If you make it a law, people will become emotional and this will bring another bad impact ... it is their religious right," he told Reuters.
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Human Rights Watch director Kenneth Roth criticized the ban: "That needless restriction means that Muslim women whose practice leads them to cover up now won't be able to leave home," he wrote on Twitter.
nm/amp (Reuters, AP, dpa)