Updated

The last Syrian troops will leave Lebanon on Sunday after 29 years, a senior Lebanese military officer said, as Damascus (search) yields to fierce international and domestic pressure after the assassination of former Prime Minister Rafik Hariri.

The announcement came as the largest number of Syrian troops to leave Lebanon in one batch vacated at least 10 positions in the northern part of the Bekaa Valley (search) in eastern Lebanon Saturday night.

Under pouring rain, dozens of trucks carrying hundreds of soldiers and at least 150 armored vehicles towing cannons and rocket launchers were seen heading to the Lebanese-Syrian Masnaa border point, witnesses said.

"Tomorrow everything will be over," the military officer told The Associated Press Saturday on condition of anonymity. Lebanese military officers rarely speak on the record.

He did not elaborate but it appeared that the withdrawal would include the Anjar base in eastern Lebanon occupied by Syria's chief of military intelligence in Lebanon, Maj. Gen. Rustom Ghazale (search).

The same officer had said earlier this week that Ghazale would evacuate Anjar by Tuesday. The withdrawal of Syrian intelligence officers along with the military has been a key demand of the Lebanese opposition.

Hariri's son, meanwhile, said he will run in Lebanese general elections scheduled to take place by the end of May.

Syria began withdrawing its troops from Lebanon last month in the wake of Hariri's killing. The assassination, for which the Lebanese opposition blamed the Lebanese government and its Syrian backers, threw the nation into political turmoil, driving out the pro-Syrian government and forcing Syria to begin withdrawing its troops. Syria and Lebanese authorities have denied involvement in the killing.

Last week, Lebanese and Syrian officials said the remaining 1,000 troops would be gone by April 26. The force stood at 14,000 troops in February, indicating the swiftness of the pullout.

Secretary-General Kofi Annan said this week he was delaying the release of a report on Syria's withdrawal from Lebanon until Tuesday so the U.N. could confirm the pullout of all Syrian forces.

Annan's chief of staff said Wednesday that Annan had spoken to Syrian President Bashar Assad and was "very optimistic" that all troops and intelligence operatives will be out of Lebanon by Tuesday.

Last September, the U.N. Security Council adopted a resolution calling on Syria to withdraw all its troops and intelligence operatives.

The United States also has been pushing Syria to withdraw its troops from Lebanon and stop interfering in the country's politics.

Syria sent troops to its smaller neighbor in 1976 to help quell what was then a year-old civil war, but the troops remained after the war ended in 1990. Damascus has been seen as holding the strings in Lebanese politics ever since.