Chief UN investigator Detlev Mehlis visited Syria again on Tuesday to question several Syrian officials on the assassination of former Lebanese Prime Minister Rafik Hariri.

"Head of the international investigation committee Mr. Detlev Mehlis arrived in Damascus today and he is expected to meet a number of Syrian persons as witnesses in the framework of his mission," the official Syrian news agency SANA said.

"Mehlis's visit to Damascus might last until the end of this week", SANA said.

Mehlis reached Syria through the border crossing of Jadeidet Yabous in a heavily-guarded convoy earlier in the day, an informed source told Xinhua.

According to the source, the chief UN investigator is expected to question Syrian Interior Minister Ghazi Kanaan, a former military intelligence chief in Lebanon, and his successor Rustom Ghazaleh who left along with Syrian troops in April.

Two of their key aides in Beirut, Mohammed Makhlouf and Jamaa Jamaa, may also be questioned.

Mehlis visited Syria on Sept. 12, when the Syrian foreign ministry agreed that he would meet with the Syrian officials.

Syrian President Bashar al-Assad has pledged full cooperation with the UN investigation team, saying Mehlis could question anyone.

Hariri was killed in a car bomb blast in Beirut on Feb. 14 and many Lebanese blamed Syria and its Lebanese allies for the killing, but Damascus denies any role.

The assassination sparked massive anti-Syrian protests and led to Syrian troops' withdrawal from Lebanon in April after 29 years of military presence under growing pressure from Washington and western countries as well as Lebanese opposition.

The UN-led investigation came to a breakthrough as Lebanon charged four pro-Syrian generals with the assassination earlier this month after Mehlis strongly recommended their arrest.

Source: Xinhua