The university could not allow the rally to be held on its campus because executives feared that a clash might erupt between pro- and anti-Thaksin campaigners, the statement said.

Moreover, a third party could manipulate the rally to cause violence between the two groups, leading to an uncontrollable situation, it said.

The PAD is launching a new round of anti-Thaksin rallies around the country amid widespread uncertainty over how the political impasse will end. The situation is further complicated by the possibility that Thaksin will re-assume the premiership after triumphing in the upcoming general election.

Since last week, numerous banners threatening the PAD and its leaders have appeared near Chiang Mai's old city walls. The city is considered the political stronghold of Thai Rak Thai party leader Thaksin, who is a native of the province.

Suriyan Thongnu-iad, a leading PAD member, said he believed local administrative bodies had fallen under Thaksin's power, and that their influence had spread to academic institutions. However, he said he respected the university's decision.

He said the local PAD group would hold a panel discussion and public meetings in place of the rally. The group will take part in a mass rally in Bangkok on September 22.