The international human rights watchdog Amnesty International is planning a new visit to Burma next month as part of its ongoing campaign for the release of the country's political prisoners. The visit closely follows a visit by the United Nations envoy for human rights.

Amnesty International says the visit early next month, its second this year, is scheduled to last more than two weeks. It says its delegation will hold talks with Burmese officials on the administration of justice, and will also use the occasion to press for freedom for the country's more than 1,200 political prisoners.

After a visit to Burma in January, Amnesty released a lengthy report calling on the military government to improve the justice system, expressing concerns among other things over the use of torture.

Among the current political detainees are members of the pro-democracy National League for Democracy party, led by Nobel Peace Prize winner Aung San Suu Kyi, who were arrested May 30 after a violent clash between a group of touring NLD officials and government supporters.

The government reported that four people were killed in that incident, but Amnesty, in its report, said it believed that the death toll was "considerably higher."

Aung San Suu Kyi was held in custody until September, at which point, after undergoing surgery for an undisclosed ailment, she was transferred to house arrest at her Rangoon residence.

The U.N. human rights envoy, Paulo Sergio Pinherio, was in Burma earlier this month, and said he was told Aung San Suu Kyi had been released from house arrest. However, Rangoon-based diplomats said Thursday that she remains isolated at her home. Mr. Pinherio said he, too, pressed for the release of all political prisoners during his visit to Burma, and later expressed frustration at the slow pace of political reform there.

He told the United Nations after his visit that a window of opportunity for pressing the military government towards greater political reform would soon close, if neighboring countries and international groupings like the United Nations failed to act.

Burma's government, under pressure from regional countries to improve its human rights policies, says it remains committed to carrying out a political reform. Prime Minister Khin Nyunt in late August released a seven-point plan for movement towards democracy.

The government says that earlier this week, it released eight of the NLD people held since the May 30 incident. It released several dozen prisoners on humanitarian grounds at the same time. Those still being detained include U Tin Oo, the NLD chairman.

U.N. Secretary General Kofi Annan, in a recent report to the Security Council, said progress towards reconciliation and democratization in Burma was yet to be achieved.