Some M23 fighters with Rwandan troops on Sunday entered the centre of another key city in eastern Democratic Republic of Congo as the African Union highlighted growing fears that the strife-torn country could break up.
The armed group reached the outlying districts of Bukavu, the capital of South Kivu province, on Friday, shortly after taking control of its airport about thirty kilometres (18 miles) away.
The fall of the city of one million people, which was barely defended by the Congolese armed forces (FARDC), gives the M23 total control of Lake Kivu, following its capture of Goma, the capital of the neighbouring province of North Kivu, at the end of January.
Growing international calls have been made for Rwanda to end its military backing for M23. It denies that its troops are in DRC.
With fears that the offensive could ignite a regional war, the international community has multiplied calls for a de-escalation and ceasefire, so far in vain.
"We don't want a balkanisation of eastern DRC," the African Union's Peace and Security Commissioner Bankole Adeoye told reporters at a summit in Addis Ababa.
Without mentioning Rwanda, he added: "We are calling for the immediate removal of M23 and their supporters from all towns and cities including Goma airport."
UN chief Antonio Guterres, speaking Saturday at the opening of the AU summit, demanded that the DRC's "territorial integrity" be respected and a regional war avoided.
The French foreign ministry called for an immediate withdrawal of Rwandan troops, while Britain on Sunday warned that the Rwandan-backed offensive risked sparking "a wider regional conflict".
The DRC claims that some 4,000 Rwandan soldiers are in the east of the country.
The conflict with M23 has lasted more than three years, with Kinshasa accusing Kigali of wanting to control the mining and trade of minerals used in batteries and electronic equipment, and also of trying to appropriate land for agriculture.
Rwanda denies the charges and says its security is threatened by armed groups in the region, notably the Democratic Forces for the Liberation of Rwanda (FDLR), created by former Hutu leaders linked to the genocide of the Tutsi in Rwanda.
