Aleppo - New UN-Arab League envoy Lakhdar Brahimi has said the death toll in Syria is "staggering" and the destruction "catastrophic" and called for a united stance from the international community.
In his first comments to the United Nations General Assembly since replacing Kofi Annan as special envoy on Saturday, Brahimi warned that the 18-month old war was "deteriorating steadily".
The former Algerian foreign minister said that a co-ordinated international approach on Syria was "indispensable and very urgent" and that he would travel to Damascus in a few days.
"The death toll is staggering, the destruction is reaching catastrophic proportions and the suffering of the people is immense," he said in a speech Tuesday to the 193-member assembly in New York.
UN chief Ban Ki-moon in his address to the assembly denounced countries sending arms to Syria.
"Those who provide arms to either side are only contributing to further misery - and the risk of unintended consequences as the fighting intensifies and spreads," Ban said.
He did not name any country but Russia is President Bashar Assad's main arms supplier while UN officials say Iran has made arms deliveries to his forces.
Assad has accused Saudi Arabia, Qatar and Turkey of arming the opposition.
On the ground in Syria, Red Cross chief Peter Maurer launched a mission on Tuesday to seek greater protection for civilians, as activists said rebel-held areas of the besieged city of Aleppo faced severe food shortages.
Maurer, president of the International Committee of the Red Cross (ICRC), met Assad in Damascus and expressed concern over the humanitarian situation in the country, ICRC spokesperson Hisham Hassan said.
In the meeting, he urged respect for international humanitarian law and stressed the need to ensure the ICRC could swiftly provide aid such as medical supplies and equipment to restore damaged water infrastructure.
State television said Assad assured Maurer that he supported the work of the Red Cross in Syria "as long as it remains impartial and independent".
100 000 fled in August
Maurer's visit, his first since taking over the post on 1 July, came amid a surge in violence across Syria, where according to the Syrian Observatory for Human Rights more than 5 000 people were killed in August alone.
Over 100 000 people fled the war-torn country in August to seek refuge in neighbouring states, the UN refugee agency said, the highest monthly figure since the beginning of the conflict in March 2011.
The Britain-based Observatory, which relies on information from a network of activists on the ground, said at least 113 people, 81 of them civilians, were killed across Syria on Tuesday.
Regime helicopters opened fire over Aleppo's Old City and the flashpoint district of Saif al-Dawla, an AFP reporter said, as sporadic shelling of residential areas of Syria's second city killed at least seven people, according to hospital records.
"We do not have the capacity to engage in frontal attacks because we only have light weapons," said fighter Ahmed Khatib after he and his men attacked an army checkpoint in the Old City with improvised grenades.
Shelling had also damaged the domed roof of a historic bathhouse in the Old City, the Al-Kawas which was built in 1392 during the Mamluk period. Residents said it was hit by a tank on Monday.
Call for investigation of journalist's death
In contrast, life returned to the streets of central Aleppo on Tuesday after advances by regime forces. Shops opened for business and residents went about their errands in the centre of the northern city.
In Damascus, fighting broke out in the Palestinian refugee camp of Yarmuk between rebels and the Popular Front for the Liberation of Palestine (PFLP), the Observatory said.
Elsewhere, a 15-year-old rebel was killed during clashes in Old Homs, in a central city which has been devastated by shelling since the early days of the revolt.
Meanwhile, the partner of Mika Yamamoto, a veteran Japanese war reporter shot dead in Aleppo on 20 August, on Tuesday urged Damascus to investigate her death.
Speaking from Tokyo he said she had been ambushed by pro-government forces.
According to the Observatory, more than 26 000 people have been killed in Syria since the revolt began 17 months ago - more than two-thirds of them civilians. The figures are impossible to verify.