Workers of London Underground have announced that they will stage two more walkouts in the row over night Tube plans.
The 24-hour strikes will start at 18-30 BTS on Tuesday August 25 and at 18:30 on Thursday August 27, the Rail, Maritime and Transport (RMT) union was quoted as saying by the British media.
Station staff will strike from 18:30 each day and drivers from 21:00.
The strikes follow two earlier walkouts on August 6 and July 8.
The walkouts forced millions of Londoners to run for alternate services such as ferries and buses. Hundreds of traffic jams were reported across London, with most congested roads around Parliament Square where delays were close to one hour.
The strikes have been called in a dispute over terms and conditions for the introduction of 24-hour train services on weekends from September.
While unions do not oppose all-night running, they are seeking guarantees about the number of weekend nightshifts drivers and other staff will be forced to work.
Unions have already rejected an offer made by London Underground (LU) and said they were left with no choice but to go ahead with the strike action.
The LU’s offer included a 2% salary increase this year, plus an extra £200 per night shift for drivers for a limited time and a £500 bonus for night Tube staff. London’s Mayor Boris Johnson described the offer as “generous”.