Israel denied on Tuesday that its forces had penetrated into Syrian territory beyond the buffer zone with the Israeli-occupied Golan Heights, after Syrian sources said the incursion had extended to within 25 km (15 miles) of the capital Damascus.

Israel carried out a wave of heavy airstrikes across Syria as its troops advanced deeper into the country, a Syrian opposition war monitor said Tuesday, and the Israeli defense minister announced that his forces had destroyed Syria's navy.

An American who says he crossed into Syria on foot has been released after seven months in detention. Travis Timmerman told the Al-Arabiya TV network in an interview

The man, who identified himself as Travis Timmerman to reporters, said he had crossed into Syria from neighboring Lebanon on a “pilgrimage” to Damascus.

American is freed after being detained for seven months in Syria.

In just over a week, Syrian rebel forces seized much of Syria’s northwest. First, the rebels captured Syria’s largest city, Aleppo, then Hama and Homs. On Sunday, they entered Syria’s capital, Damascus, taking the city without a fight as government forces fled.

Syria's interim government vowed on Thursday to institute the "rule of law" after years of abuses under ousted president Bashar al-Assad, as the United States warned against any action that risked triggering further conflict.