Lebanon's leaders have called for calm in the wake of the assassination of Saleh Aridi, a Lebanese Druze politician, whose death in a car bombing has threatened to derail efforts at national reconciliation.

Michel Sleiman, the Lebanese president, had ordered the Lebanese army to step up security in the area on Thursday and launch an investigation into the incident.

Aridi's death on Wednesday came less than a week before planned reconciliation talks among rival Lebanese factions.

The attack was thought by politicians to be an effort to rekindle violence between rivals in the sensitive Druze-inhabited mountains, areas controlled by the two main Druse factions - the Lebanese Democratic Party led by Talal Arslan and the Progressive Socialist Party of Walid Jumblatt.

'Unity threatened'

Arslan said the perpetrators were targeting "unity and co-existence" among the Lebanese people, calling Aridi a martyr and promising that the work he made on peace in Lebanon would continue.

Ghazi Aridi, Lebanon's minister for transportation and public works, said: "This crime is no doubt targeting all that has been achieved since the Doha agreement".

It was the first such assassination since an Arab-brokered agreement was reached after sectarian fighting in May involving Shia Hezbollah fighters and pro-government Sunni and Druze factions.

Al Jazeera's Sherine Tadros in Beirut said: "The significance in this assassination is more in terms of the timing and that Lebanon is looking toward a period of reconciliation".

The bombing also comes as Lebanon's political parties are preparing to hold a national dialogue meeting next week in an attempt to resolve outstanding difficulties.

Aridi, who was in his 50s, was alone in his car when the bomb detonated, the officer said.

While an investigation is still under way, there have been no claims of responsibility for the attack have been reported, but many residents fear the assassination might stall national reconciliation in the country.

Farid al-Aridi, a Baysur resident, said the aim of the assassination was to "create a division in the village".

"Aridi is a great loss for the village and for the Druze sect. He was a lovely man in the village.

The aim was to create a division in the village because until now the village has been far away from any division and we haven't been frightened," he said.