The meeting of the 15-nation Southern African Development Community (SADC) comes on the heels of recent crackdowns on anti-government protests in Malawi and Swaziland, which join the other crises on the list of regional leaders' headaches.
The SADC is under pressure to show its commitment to democracy in the region at the summit in the Angolan capital, Luanda, but Wednesday's opening ceremony made no direct references to the spreading political turmoil.
Angolan President Jose Eduardo dos Santos said in a written welcome message that the summit would allow regional leaders to "harmonise our positions regarding key current affairs issues that may affect the peace and stability necessary to ensure sustainable development and the consolidation of democracy."
But dos Santos, the SADC's incoming chair, did not mention what a group of southern African civil society leaders described last week as the region's growing list of "problem cases".
Namibian President Hifikepunye Pohamba, the organisation's outgoing chair, said "progress" had been made by SADC mediation teams trying to resolve the protracted stand-offs in Zimbabwe and Madagascar, but did not elaborate except to say that "all these issues were dealt with" at an SADC meeting in June.
The SADC has been criticised for dragging its feet in the Zimbabwe and Madagascar crises, which its mediators have so far failed to definitively resolve.
In Zimbabwe, long-time President Robert Mugabe and Prime Minister Morgan Tsvangirai are deadlocked over when to hold new elections.
The two leaders share power in a tense "unity government" formed to halt the country's economic and political tailspin after a bloody and contested presidential election in 2008.
Mugabe insists new polls go ahead this year, with or without the new constitution agreed to in the power-sharing deal. Tsvangirai wants reforms to be implemented first.
Regional mediators also have yet to find a solution to the impasse in Madagascar, which was suspended from the SADC in March 2009 after elected president Marc Ravalomanana was ousted by Andry Rajoelina, then mayor of the capital Antananarivo.
There was no chair for the Indian Ocean island nation at the summit's opening ceremony.
Malawian President Bingu wa Mutharika was also notably absent from the summit.
His country was shaken last month when 19 people were killed as security forces used live ammunition to put down demonstrations against Mutharika, whom protesters accused of becoming increasingly autocratic amid an economic downward spiral.
After the deadly unrest, the SADC sent an observer mission to the country that is expected to report back to the summit.
Malawian police tightened security in main cities Wednesday in case of more protests, even though organisers had a day earlier postponed nationwide vigils.
Swaziland's King Mswati III, Africa's last absolute monarch, also faces growing anti-government sentiment. The tiny kingdom erupted in protest in April over proposals to slash government workers' salaries amid a financial crisis that has seen Mbabane beg South Africa for money.
Copyright AFP (Agence France-Presse), 2011