Rwanda's suitability for Commonwealth membership this year has been questioned because of its human rights record.

Diplomatic efforts accelerated on Wednesday to resolve the crisis in Kenya, where post-election violence has threatened to escalate into tribal war, with tens of thousands displaced and hundreds murdered. The dispute over last week's presidential ballot has triggered Kenya's worst urban unrest in 25 years.

The Commonwealth's biennial summit opened on Friday in Uganda with leaders focusing on climate change, a day after Pakistan, which is still under emergency rule, was suspended from the organisation. The loose federation of mostly former British colonies includes some of the world's major polluters.

Commonwealth leaders are aiming to reach a decision by the end of the weekend on whether to make former Belgian colony Rwanda a new member, the head of the 53-nation grouping said on Thursday. Commonwealth heads of government are meeting in the Ugandan capital, Kampala, from Friday.

Former Pakistan prime minister Benazir Bhutto threatened on Wednesday to lead a mass protest march to the capital unless President Pervez Musharraf quits as army chief, holds elections and restores the Constitution. Bhutto, the politician most capable of mobilising street power, gave Musharraf until Friday to comply.