Lucknow, Dec 30 (IANS): Heavy fog continued to disrupt air, rail and vehicular traffic in most parts of Uttar Pradesh for the second consecutive day on Saturday, slowing down normal life as the cold wave intensified.

Visibility dropped to one metre on many state and national highways, leading to several pile ups and accidents.

Six persons of a family, including an infant, were killed on the Lucknow-Agra Expressway late on Friday when a speeding truck on the wrong side rammed into their car.

Despite police orders, heavy vehicles continued to ply on the expressway, endangering commuters lives.

All schools upto Class 8 have been closed till January 4, following the the state government's order. Timing of senior classes has also been changed to later in the day.

The Regional Met Office has predicted foggy days to hold ground for the next few days.

Vehicular traffic has been hit by the poor visibility and the rail traffic has been completely disrupted.

More than 190 trains were running late on the Northern (NR), North Eastern (NER) and the North Central Railways (NCR) divisions.

Major trains that were running behind schedule included Lucknow-Chandigarh Express, Vaisahali Superfast to New Delhi, Lucknow Mail, Padmawat Express, Sabarmati Express and Shatabdi Express between Lucknow and New Delhi.

The humidity levels have been 100 per cent in the past 24-hours in eastern and central parts of Uttar Pradesh while the western parts are going dry.

The maximum temperature in major cities of the state was hovering around 18 degrees Celsius, adding to the winter bite.

The cold wave was likely to intensify in the coming days and relief in the form of sunny days would come only in the New Year, weatherman said.