Syrian opposition forces claim that they have shot down a regime warplane in the eastern province of Deir Ezzor.

"The opposition forces shot down the plane and captured its pilot," the Local Co-ordination Committees (LCC) activist network said on Monday.

The LCC posted videos on YouTube that they allege is of the jet being downed, and then another of the plane's pilot giving a statement. The state news channel Syria TV said the plane crashed due to technical problems during a "regular training mission" and a search party was under way.

State news agency SANA said the pilot had ejected from the plane before it crashed.

Shops raided

On the outskirts of Damascus, the capital, shells struck opposition strongholds from before dawn on Monday.

Activists said more than 45 people, including 36 civilians, had been killed in the past 48 hours in the area.

Security forces reportedly arrested at least 21 people as they raided houses and shops in the center of Damascus on Monday.

The Syrian Revolution General Council, a network of activists on the ground, said that armed forces had broken down the doors of shops that had closed in a show of defiance against the regime.

Activists said the raid was the biggest operation of its kind in the city since the launch of the uprising against Assad's regime in March last year.

Rami Abdel Rahman, of the UK-based Syrian Observatory for Human Rights, said: "This is not the first time there have been raids in central Damascus, but this is the first time something like this has happened on such a large scale."

Security forces also swept into a graveyard "under the pretext of searching for weapons", he said.

The group also reported that several houses had been burned in Basateen al Mezzah, in the capital, and that there were additional clashes in the outskirts of Damascus outskirts, where armed rebels were able to destroy some heavy military vehicles.

Fighting also raged in the city of Aleppo, with opposition fighters seeking to establish a strategic foothold in the north.

Clashes were reported in the southwestern district of Salaheddin, from which opposition fighters fled last week, but has seen continued clashes.

Syrian troops were advancing on the southwestern opposition fighters stronghold of Sukari, security sources said.

Activists on Sunday said "communications of all forms" were cut in most of Aleppo city and its suburbs.

Syria visit

On Monday, UN humanitarian chief Valerie Amos announced that she is to visit Syria and Lebanon amid growing concern over the "deteriorating humanitarian situation".

The visit, planned from August 14 to 16, "aims to draw attention to the deteriorating humanitarian situation in Syria and the impact of the conflict on people either remaining in Syria and who have fled to other countries, including Lebanon", the UN office for the co-ordination of humanitarian affairs said in a statement.

While in Syria, Amos is expected to discuss ways of "urgently scaling-up relief efforts and reducing the suffering of civilians caught up in the fighting with the Syrian authorities, the Syrian Arab Red Crescent and other humanitarian partners".

The Organization of Islamic Co-operation (OIC) summit are to meet in Mecca on Tuesday.

An unnamed diplomat there told the Reuters news agency that Syria will "most likely" be suspended from the OIC, a move Iran opposes.

PHOTO CAPTION

Image made from amateur video released by the R.Y.E. Syria shows a Syrian plane downed over the eastern province of Deir el-Zour, Syria, Monday Aug. 13, 2012.

Al-Jazeera