HANOI (REUTERS) - Vietnam widened lockdown measures in its industrialised north on Tuesday (May 25) to combat its biggest Covid-19 outbreak so far, as the authorities reported a daily record in new cases that was more than double the previous high.

The Health Ministry announced 457 new Covid-19 infections on Tuesday, the biggest jump since the 190 cases seen on May 16, driven by clusters in factory zones in two northern provinces.

Bac Ninh, home to production facilities of Samsung Electronics, started a curfew and other travel restrictions on Tuesday, state media reported.

That followed the temporary closure of four industrial parks, including three with Foxconn facilities, by the authorities in neighbouring Bac Giang province.

The outbreak could be a big challenge for Vietnam, which successfully contained earlier, smaller outbreaks and avoided the level of economic damage suffered by many of its neighbours.

Bac Ninh and Bac Giang are the epicentre of the new outbreak that has infected more than 2,800 people since late April, including hundreds of factory workers.

The authorities say the outbreak, which accounts for nearly half of Vietnam's overall cases, has spread to more than 30 of the country's 63 cities and provinces.

Hanoi on Tuesday shut down restaurants and banned gatherings at public areas, including physical exercises in parks. The Vietnamese capital has recorded 220 cases since late April.

Most of cases on Tuesday were at factories in Bac Giang, where the authorities said testing had been ramped up and all workers' dormitories put in isolation.

Vietnam has reported at least 5,860 infections in total, with 44 deaths. It has yet to start mass inoculations against the coronavirus, with about 1 million doses of vaccines administered so far, mainly to front-line workers.