MUMBAI: A large number of suburban and long-distance trains will be affected on the intervening nights of April 11 and12 and April 12 and 13 due to a mega block for the “re-girdering” of a bridge between Mahim and Bandra stations in the city, the Western Railway said on Wednesday.

The duration of the block on each night will be 9.30 hours, it said in a release.

On April 11, the block will start (train traffic will stop) at 11 pm and end at 8.30 am next day. On April 12, the block will start at 11.30 pm and conclude at 9 am next day.

However, the exact block timings will vary for fast and slow lines.

“During the execution of the work, a few suburban services as well as Mail/Express trains will be affected,” said Vineet Abhishek, Chief Public Relations Officer of the WR.

As many as 334 trains will be fully cancelled — 132 on the first day and 202 on the second day, while 185 services will be partially cancelled — 68 on the first day and 117 on the second day.

The WR has planned to operate 110 extra services — 42 on the first day and 68 on the second day — to clear the extra rush of passengers.

Nine long-distance trains will be partially cancelled, while nearly 11 other trains will be either regulated or rescheduled due to the block.

Western Railway’s suburban network extends between Churchgate in south Mumbai and Dahanu Road station in the neighbouring Palghar district. More than 30 lakh passengers travel daily by its suburban services.