The visiting UN under-secretary general for humanitarian affairs, Valerie Amos, said Thursday that the devastation in Baba Amr neighborhood in Homs is "significant," saying that she was "struck" by what she saw there.

Amos, who is on a three-day visit to Syria, went to Homs Wednesday for "an assessment visit" with the Syrian Red Crescent and representatives of the international Red Cross.

"I have been struck by the difference between what I have seen here in Damascus and what I saw yesterday in Baba Amr," Amos told reporters Thursday following her meetings with Syrian ministers of education and health.

"The devastation there is significant... That part of Homs is completely destroyed and I am concerned to learn what happened to the people in that part of the city," she said.

Meanwhile, Amos is due to meet the head of Syrian Red Crescent Thursday for talks about the aid relief activities in restive areas.

Amos arrived in Syria's capital of Damascus after midnight Tuesday and held talks Wednesday with Syria's Foreign Minister Walid al-Moallem before heading to Homs, during which al-Moallem reiterated Syria's commitment to cooperate with Amos mission to Syria, "so long as it respects Syria's sovereignty and independency."

Amos' visit to Syria meant to convince the authorities of allowing unhindered humanitarian access to restive Syrian cities, mainly Homs.

Baba Amr has emerged as the epicenter of armed confrontation between troops loyal to Syrian President Bashar al-Assad and armed rebels comprising partly of army defectors.

Activists said Baba Amr has been under the army's bombardment for nearly a month, and hundreds of people have been killed in the area since Feb. 4, when the Syrian army started its assault on " armed groups."

The government said it was fighting armed terrorist groups and al-Qaida members, who have reportedly infiltrated into Syria to fight alongside the rebels.

Local and foreign reports said that al-Qaida fighters are sneaking from Iraq to Syria to join Sunni insurgents in their battle against the Damascus regime, which is dominated by a Shiite offshoot sect.

The Syrian government has accused some Arab and Western countries of providing weapons and financial support to the armed groups in Syria. It said in December 2011 that "armed terrorist groups" had killed more than 2,000 army and security personnel during the unrest.

The United Nations said recently that "well over" 7,500 people have died in Syria's violence.