Saudi Railways Organisation said the Haramain high-speed link connecting Makkah with Madinah is deep into its construction phase after earlier delays which saw the planned opening date slip by a year.

The line’s station in Madinah is now 52 percent complete, with the Makkah terminal and a stop in Jeddah about a third built and one serving King Abdullah Economic City almost 38 percent done, Wasmi al-Ferraj, director general of expansion projects at Saudi Railways, said at a news conference in Riyadh. A fifth station will serve Jeddah International airport.

The Haramain link, which is being constructed specifically for high-speed electric trains, will be 450km (280 miles) long and allow trains to reach at least 300kmph, linking Islam's two most popular pilgrimage destinations.

It is due to open by the end of December 2015, the executive said.

The project has been divided up into six sections or “areas”: Area 1 starts in Makkah and runs to the 70km mark; Area 2 runs from 70km to 100km; Area 3 from 100km to 185km; Area 4 from 185km to 285km; Area 5 up to 350km; and Area 6 to the end of the 450km track in Madinah.

The line will cost almost $12bn, with the first phase, split into two parts, having a budget totaling $4.1bn and the second - which includes the tracks and signalling - some $7.9bn, Al-Ferraj said in an interview following his presentation.