Police on Friday resumed the grim task of searching for the bodies of two children who were swept away while trying to cross the Freystata River at Mount Fletcher in the Eastern Cape.

Six children were swept away while attempting to cross the river on Wednesday. Four  bodies have been recovered.

Police spokesperson Capt Khaya Tonjeni said the search had resumed on Friday.

"The search-and-rescue team is still on site but it is quite difficult because the waters are very dark and muddy," said Tonjeni.

"There was also some erosion which occurred so there are trees and branches in the river that the searchers need to make their way through," he added.

Tonjeni said the water was still travelling quickly, meaning the search area needed to be widened as the children could easily have been carried lower down the river.

He painted a sombre mood at the village where the children were from, saying people  were in mourning.

"To lose one child is one thing but to lose six is just something else," he added.

The children were aged between six and eight.