She was stopped by police 15 miles outside the capital after making her fourth attempt in as many weeks to meet provincial MPs belonging to her National League for Democracy (NLD) party.
Each time, the NLD leader and Nobel Peace Prize winner has been stopped by State Peace and Development Council government forces.
Last time, Ms Suu Kyi, 53, was involved in a six-day confrontation with the junta, who eventually brought her back to the capital by force.
A Rangoon-based diplomat said this time Ms Suu Kyi had been stopped on her way to Bassein, 75 miles west of Rangoon. "It looks like we are in for more of the same," said the diplomat. "They have more supplies: they are better prepared to sit it out this time." The junta said in a statement that Ms Suu Kyi tried to enter Irrawaddy Province "without proper security arrangements".
Burma watchers in Thailand say it is part of Ms Suu Kyi's strategy to put pressure on the junta ahead of a 21 August deadline for it to convene a parliament elected in 1990. The NLD won the 1990 poll by a landslide but it and other parties have never been allowed to take up their seats.
Meanwhile, 18 foreigners arrested last Saturday for handing out pro-democracy leaflets in Rangoon have spent their fourth day in detention.
A Bangkok-based activist said this could be the year for democracy in Burma. "Something is definitely going to happen soon," she said. "Things might not happen on the 21st but they could shortly after that." The activist, who declined to be named, said Ms Suu Kyi's forays into the provinces could also be a diversionary tactic to take the heat off other NLD leaders who wanted to organise the party's response to any failure by the junta to meet its demands.
International companies in Burma are also clearly nervous. The US oil company Arco said it would cease operations in October, having invested $50m. There were reports that the French firm Total was pulling out 250 families, and other firms have shut offices.Reuse content