The armed rebels have been intensifying violence in Syria with a purpose of achieving gains on the ground before embarking on negotiations with President Bashar al-Assad's administration, observers said.

Since last week, the rebels reinforced their attacks at the eastern and northern suburbs around the capital Damascus, while over the past two days, the armed rebels have reportedly seized a number of government and army establishments and overrun a town in the country's north.

The Syrian Observatory for Human Rights said that the rebels have overrun the Al-Jarrah air base in the northern province of Aleppo on Tuesday, a day after they allegedly took control over the country's largest Al-Furat dam in the northeastern town of Tbqa.

The capture of the Al-Jirah base took place after days of clashes in the vicinity of the airport, and is considered one of the largest operations by the rebels after storming the Taftanas air base in northern Idlib province.

The rebels' recent tactic is to attack air base and military sites across the country in a bid to undermine the Syrian army, analysts say.

Hasan Abdul-Azim, head of the oppositional National Coordination Body, said the recent escalation in military showdown by the rebels aims at enhancing their positions and achieving as much gains as they can on the ground before sitting down for talks.

In an interview with the pro-government al-Watan daily released Tuesday, Abdul-Azim said his party welcomes the dialogue initiative called for by the head of the opposition coalition in exile, Moaz al-Khatib.

Last week, al-Khatib made a surprising statement by declaring his readiness to negotiate with the Syrian administration over the departure of Assad's government, provided that the pro-Assad security forces release as many as 160,000 detainees from jails. He also demanded that the negotiations be held with Vice President Farouq al-Sharaa as a representative of the Assad's administration.

The government has not officially responded to the initiative so far. However, analysts and some officials said the dialogue should not be pre-conditioned. They also added that the number of detainees that al-Khatib asked for their release is exaggerated.

Yet, some Western reports indicated that the Syrian Minister of National Reconciliation, Ali Haidar, is ready to negotiate the detainees issue with al-Khatib.