According to reports received here, the wall will be built from near the border town of Taftan, about 700km west of Quetta.

"The Iranian authorities started work on the wall about a month ago," according to Barkat Ali Khan, a Pakistani border town administration official.

"The concrete wall will be 10 feet high and 3 feet wide," he said, adding that hundreds of workers could be seen building the wall.

He said that the Iranian authorities appeared to be in a hurry to complete the project.

"I think they want to seal the border with Pakistan to stop illegal crossings from both sides and check drug smuggling," Mr Barkat said, adding that the wall would be up to the Mand area in the Turbat district of Balochistan.

Pakistan and Iran already fenced their border at different points a long time ago.