Train passengers face another day of disruption as union members at four rail firms stage the latest 24-hour strikes in disputes over safety.

Services on Greater Anglia, Merseyrail, Northern and South Western Railway, including its Isle of Wight Island Line, are likely to be affected on Wednesday.

RMT union members also walked out on Monday and plan to again on Friday.

The Department for Transport denied the dispute was about safety.

It said rail companies would "keep passengers moving".