Lebanese investigating magistrate Elias Eid has accused the four traders of forgery and withholding information that could have helped the investigation into the former prime minister's death, a court official said on Thursday, speaking on condition of anonymity because of the sensitivity of the probe into al-Hariri's killing.
A second court official said the four traders were accused of providing mobile phone lines to those who planned and carried out al-Hariri's assassination.
The official, who also spoke on condition of anonymity because of the sensitivity, said the chips for the mobile phones were later destroyed in a bid to eliminate traces.
The arrests had been requested by the chief UN investigator into the al-Hariri killing, Detlev Mehlis.
French and German experts assisting the UN investigation have studied thousands of calls made before and after the assassination.
The phone dealers were among 10 detained for questioning early this week, the officials said.
Syria has expressed 'satisfaction'
with Mehlis' investigation (L)
The four were formally arrested on charges on Wednesday and the remainder were released on bond.
The arrests mean that Lebanon has eight people in custody on charges related to al-Hariri's murder.
Last month it detained four pro-Syrian generals, three of whom ran Lebanon's security services at the time al-Hariri was killed. The fourth is still commander of the presidential guards.
The generals have been accused of complicity in the assassination.
Lebanon's pro-Syrian president meanwhile has rejected a call from his prime minister to step down.
The call by the prime minister, who is backed by anti-Syrian politicians, brought into the open a simmering conflict with the increasingly isolated President Emile Lahoud, who has repeatedly refused to resign despite mounting pressure.
Prime Minister Fuad Siniora had until now avoided a direct call for Lahoud, one of the last holdovers of Damascus' diminishing power in Lebanon, to step aside.
"Personally, I believe after the indictment of these four people, he should resign," Siniora said in an interview with the Washington Post published on Thursday.
"Personally, I believe after the indictment of these four people, he should resign"
Lebanese prime minister
Siniora, who is on an official visit to Washington, also said Lahoud had been imposed on Lebanon by Syria, and that the majority of Lebanese now oppose him.
Lahoud expressed his "astonishment" at Siniora's comments and said there was nothing that warranted his resignation.
The president "will continue to shoulder his responsibilities until the end of his term", he said in a statement issued by his office.
Lahoud's presidency ends in the fall of 2007.