At least 43 people were killed Saturday in violence in Syria, reported opposition activists, despite overnight criticism of the killings of civilians from the United Nations Secretary General Ban Ki-moon, dpa reported.
Most of the deaths were civilians in the central provinces of Hama and Homs, said the activists. The areas are key opposition bastions in a revolt against the rule of President Bashar al-Assad.
At least 36 people were killed when military forces shelled the area of al-Latmana in Hama, reported the opposition Syrian Observatory for Human Rights.
Four others were killed in a military attack on the area of Tibat al-Imam on the outskirts of Hama, added the Britain-based observatory.
Three civilians, including a woman and her child, were killed when security forces attacked the area of al-Kussiar in Homs, said the group.
Rebels, meanwhile, attacked the Minakh air base, on the outskirts of Aleppo, Syria's third-largest city, said activists.
There were no reports about casualty figures.
News from Syria is hard to verify as the government has barred independent journalists from restive areas since the uprising started in March 2011.
Ban has said an agreed 10 April ceasefire deadline for Syria was "not an excuse for continued killing."
He deplored in a statement late Friday the assault by the Syrian troops against "innocent civilians, including women and children, despite the commitments by the government of Syria to cease all use of heavy weapons in population centers."
Syria has said it accepted a peace plan proposed by international envoy Kofi Annan aimed at ending the conflict, in which more than 9,000 have been killed, according to the UN.
Annan's plan calls on the Syrian government to pull back its troops and heavy weapons from civilian areas, and for all parties, including the opposition, to cease armed violence within 48 hours of this withdrawal.
It also calls for the release of detainees, access to humanitarian services, and talks between the Syrian government and opposition.
The opposition has accused al-Assad's government of intensifying its attacks on dissident areas in the run-up to the April 10 truce deadline.
Syria's official news agency SANA, meanwhile, said Damascus had sent letters to Ban and the president of the UN Security Council, US Ambassador Susan Rice, telling them that "terrorist acts" were on the rise.
"The terrorist acts committed by the armed terrorist groups in Syria have increased in the last few days, particularly after reaching an understanding on Kofi Annan's plan," SANA quoted the letter as saying.
Damascus has demanded a written commitment that the opposition would not take advantage of the withdrawal to make territorial gains, according to the agency.
Syrian state media reported that Foreign Minister Walid al-Moallem was expected to visit Moscow on Monday for talks on "the latest developments."
Russia, a main supplier of arms to the Syrian government, has along with China vetoed two UN Security Council resolutions against Damascus.