State media: The UAE has handed lengthy prison sentences to 57 Bangladeshi expatriates for protesting against their government while in the Gulf country where demonstrations are banned, state media reported Monday.

Protests have swept Bangladesh this month against a quota system for civil service jobs that critics say benefits supporters of Prime Minister Sheikh Hasina's 15 years of autocratic rule.

The near-daily marches escalated last week into civil unrest which has left 163 people dead. More than 500 people, including some opposition leaders, have been arrested in Dhaka since the violence began, according to police.

On Monday, the official Emirati news agency WAM said three Bangladeshi expatriates were sentenced to life, 53 others to 10 years in prison and one to 11 years for participating in alleged protests.

The defendants had "gathered and incited riots in several streets across the UAE on Friday," WAM said, adding they would be deported after the completion of their prison terms.

The charges follow a swift investigation that was ordered on Friday, according to WAM.

A witness confirmed "that the defendants gathered and organized large-scale marches in several streets of the UAE in protest against decisions made by the Bangladeshi government," it added.

The UAE, an autocratic federation of seven sheikhdoms, is populated mostly by expatriates, many of them south Asians who work as laborers.

Bangladeshis form the third largest expatriate group in the UAE, after Pakistanis and Indians, according to the UAE foreign ministry.

The oil-rich Gulf state bans unauthorized protests and prohibits criticism of rulers or speech that is deemed to create or encourage social unrest.

Defamation, as well as verbal and written insults, whether published or made in private, are punishable by law. VOA/SP