The head of the UN mission in the Democratic Republic of Congo has ordered peacekeeping troops to act to protect civilians after shelling hit areas near the eastern city of Goma in renewed fighting between the army and M23 rebels.
Martin Kobler, head of the mission known by its French acronym MONUSCO, said populated areas and UN positions had been directly attacked during the clashes on Thursday.
"I have ordered the MONUSCO Force to react and to take necessary action to protect civilians and prevent an advance by the M23," he said, without elaborating.
The fighting close to Goma, a city of a million people on the Rwandan border, comes after a relative lull in the 18-month rebellion.
Late last month, the UN pledged to keep the M23 rebels - named after a peace agreement they signed with the government in March 2009 - out of range of the town, which they briefly seized last year.
Rwanda, which has long had strained relations with its western neighbour, accused the Congolese army of deliberately firing artillery into its territory. Congolese authorities denied the reports and repeated their accusation that Rwanda backs M23, a charge that Rwanda denies.
Three shells landed in Goma and there were two bodies of children killed in one of the explosions, a Reuters correspondent in the city said.
Another civilian was killed and four others wounded, officials at a local hospital said. Two Congolese soldiers were also wounded, they said.
Fighting initially broke out late on Wednesday.
A senior UN official, who asked not to be named, said that on Thursday that the rebels entered a security zone surrounding Goma, which was established by a new, robustly-mandated UN Intervention Brigade earlier this month.
The official said M23 had fired the shells that fell on Goma and across the border in Rwanda.
Rwanda's Defence Ministry acknowledged a rocket had hit the border village of Buga but blamed it on the Congolese army, calling it "completely unprovoked and senseless".
No casualties were reported in Rwanda, but the ministry said the explosion had damaged property.
In New York, deputy UN peacekeeping chief Edmond Mulet asked the UN Security Council to condemn M23's attacks, diplomats told the Reuters news ageny on condition of anonymity.
France drafted a council statement that would have "condemned in the strongest terms the attacks by M23 rebel group against civilians" and M23's attacks on MONUSCO, according to a draft seen by Reuters.
But the delegation of Rwanda, currently a council member,objected to that wording and proposed an amended text, also seen by Reuters, that would condemn both the Congolese army and M23 and urge the Congolese military and M23 to cease violence immediately".