Play in the US Masters is expected to resume at around 10.25 pm (Irish time) after the third round was suspended earlier because of the threat of approaching lightning  and thunderstorms.

Players had been on the course for 2-1/2 hours when the sirens sounded at 5 p this afternoon.

Officials initially expected the delay to last "approximately one hour" but later said a further decision would be announced.

"The progress of the storm is being continuously monitored," Will Nicholson, chairman of the competition committee, said in a statement. "As decisions are reached, appropriate bulletins will be issued."

With the weather forecast for the Augusta area predicting isolated thunderstorms and rain, plus possible hail, throughout the afternoon, the third round is likely to be carried over into Sunday.

Tournament leader Chad Campbell of the US, who moved three strokes clear after firing a five-under-par 67 in the second round, had been scheduled to tee off at 7.50 pm.

The Irish challenge of Padraig Harrington (-1) and Darren Clarke (-2) have also been forced to wait.

After the first two rounds at Augusta National were played in bright sunshine and fast-running conditions, the par-72 layout will play longer and softer over the weekend with more receptive greens.

Rain has intervened at the last four Masters, including a complete washout on the scheduled opening day in 2003.

Eight of the last nine editions have been hit by rain, although a Monday finish has not been needed at Augusta since 1983 when Spaniard Seve Ballesteros claimed his second green jacket.

Sunday's weather forecast is optimistic, with dry and partly sunny conditions expected.