Prime Minister Dr Mahathir Mohamad made a surprise visit to his rival, opposition leader Fadzil Noor, who remains unconscious six days after a heart bypass operation, officials said Saturday.

Mahathir visited Fadzil, who is president of PAS, on Friday as an act of goodwill, a spokesman said.

He said the premier made the decision on the spur of the moment.

"We all missed it. He just decided on the spot, on the way back home Friday," he told AFP .

"It's a good thing that despite their differences, there is a sign of concern," a spokesman for Fadzil, political secretary Hatta Ramli told AFP .

Fadzil is in intensive care after a heart bypass operation on Monday.

According to Hatta doctors have said the PAS leader had made some improvement but could not predict when he would regain consciousness.

Stand in leader

On Thursday, deputy prime minister Abdullah Ahmad Badawi made a similar visit to the opposition leader.

The Islamic party has already appointed deputy president Abdul Hadi Awang to stand in for Fadzil during his illness.

Abdul Hadi is chief minister of the PAS-ruled Terengganu state, which has announced plans to introduce strict Sharia laws next month, and he is seen as more of an Islamic hard-liner than Fadzil.

PAS made strong gains in 1999 general elections, but analysts say the Islamic party has seen its support eroded in the wake of the Sept 11 terror attacks on the United States.

PAS holds 27 of Malaysia's 193 federal parliament seats and controls two states - Kelantan and Terengganu - out of a total of 13.

Analysts have suggested that Mahathir may take advantage of PAS's perceived weakness to call an early general election, which is not scheduled until 2004.