BEIRUT, Aug 30: UN investigators questioned an aide to Lebanon’s pro-Syrian president and three former security chiefs on Tuesday as suspects in the killing of ex-prime minister Rafik al-Hariri, the prime minister said.

Lebanese police detained the three top security officials in dawn raids, the first concrete steps towards implicating allies of Syria in the February killing that shook Lebanon and hastened the departure of Syrian troops after three decades.

“The detentions in Beirut are the beginning of justice,” Hariri’s son, member of parliament Saad Hariri, told Arab television news channel Al Arabiya from Paris. “This is a start ... There will be more detentions.”

The fourth man named as a suspect, Republican Guard commander Mustafa Hamdan, voluntarily went to the headquarters of the UN investigating team.

A close aide of pro-Syrian President Emile Lahoud, he was the only pro-Syrian security official to keep his job after parliamentary elections three months ago ushered in an anti-Syrian majority.

“They were summoned ... to be interrogated as suspects,” Prime Minister Fouad Siniora said of the four after talks with the chief of the UN investigation team, German prosecutor Detlev Mehlis.

Siniora told reporters that Jamil al-Sayyed, former head of General Security, Ali Hajj, ex-chief of police, and Raymond Azar, former military intelligence chief, had been detained at Mehlis’s request.

Hariri’s killing, which many in Lebanon blamed on Damascus, sparked mass anti-Syrian demonstrations in Beirut. Syria denied any involvement but bowed to world pressure and pulled its 14,000 troops out of the country in April after 29 years.

Mehlis was holding talks with the premier as news of the arrests broke, and later met Justice Minister Charles Rizk. A UN official in Beirut refused to comment.

“According to what prosecutor Mehlis told me, their questioning will determine the coming steps taken against them,” Siniora said, adding that a staunchly pro-Syrian former member of parliament was also summoned for interrogation.

Some Lebanese politicians had accused the four officers of a role in the deaths of Hariri and 20 others in a large bomb blast in Beirut.

Mehlis already hinted last month that Hamdan, who was first questioned in June, was involved in a cover-up of the killing.

The UN team probing the killing is expected to report its findings to the Security Council in the next few weeks.

Some Lebanese welcomed Tuesday’s moves, but some were worried the outcome of the investigation could fuel more unrest.

“I am happy the truth will soon be revealed but I am afraid the truth could mean turmoil and more explosions,” said Sami al-Arab, a 23-year-old chef.

The UN team asked local police for the raids to bring in the former officials for questioning and search their homes, the Lebanese Justice Ministry said in a statement. It said a judge had approved the move.

It said Mehlis had promised to inform the judge of the interrogation results and pass on recommendations, but the fate of the detainees was in the hands of local authorities.

Police also raided the home of pro-Syrian former MP Nassir Qandil but did not find him. Family sources said Qandil was in Damascus but would return shortly to face the investigators.

Syrian President Bashar al-Assad said in an interview published on Sunday that Damascus would cooperate fully in the Hariri murder probe after Mehlis criticized it for not doing so.—Reuters