The announcement about the defendants, Michel Samaha, the former minister, and Mr. Mamlouk, a Syrian security official, came amid increased sectarian tensions in Lebanon that are directly tied to the nearly two-year-old conflict in neighboring Syria, which occupied Lebanon for nearly three decades until 2005 and still deeply polarizes Lebanese politics.
Lebanese officials have said explosives were found in a car belonging to Mr. Samaha, who was arrested on Aug. 9. Mr. Mamlouk was accused of plotting with Mr. Samaha to transport the explosives into the country. An arrest warrant for Mr. Mamlouk was issued this month. His whereabouts is unclear.
It also was unclear how long a trial would last or whether the judge’s recommendations of punishment would be followed if the pair were found guilty. But the Lebanese government’s handling of the politically sensitive case carries its own risks of aggravating sectarian tensions in this country.
On Tuesday, a group claiming to represent a faction of Syrian rebels threatened to lob mortar shells into Lebanon to attack Hezbollah, the Shiite militia that is also Lebanon’s most powerful political party, in retaliation for what rebels say is a Hezbollah military campaign against rebels in Syria. The statement warned Lebanese citizens, especially in the Shiite, pro-Hezbollah border town of Hermel, to stay away from Hezbollah positions that it said were shelling the rebels across the border.
A cross-border skirmish between Hezbollah and Syrian rebels could be a dangerous escalation in Lebanon, which has struggled to stay out of the conflict in Syria.
Representatives of the main group of rebel fighters, the Free Syrian Army, issued conflicting statements, with one saying the threat was a provocation fabricated by Hezbollah, and another confirming it and giving Hezbollah 48 hours to end its attacks or face retaliation.
Hezbollah is closely allied to the Syrian government, while its Sunni rivals in Lebanon largely support the majority Sunni rebels. Rebels say Hezbollah has stepped up its military activity inside Syria, taking over numerous villages near the border. Hezbollah says its fighters have been active only in Syrian villages where Lebanese citizens live and are defending themselves.
With the Syrian conflict threatening to destabilize the region, Russia’s foreign minister said on Wednesday that his country would work with the Arab League to bring about direct talks between Syria’s government and the armed opposition in a bid to end the deadly civil war.
Speaking after a meeting with Arab League officials in Moscow, the minister, Sergey V. Lavrov, told reporters there were “signs of tendencies for dialogue from both the side of the government and the opposition,” Agence France-Presse reported.
Russia has long called for a political solution, but Mr. Lavrov’s statement seemed to indicate a new level of engagement in pushing for talks. Syria’s foreign minister, Walid al-Moallam, is scheduled to visit Moscow on Monday for talks, and the president of Syria’s main opposition coalition, Moaz al-Khatib, is expected to visit Moscow in March, Mr. Lavrov said.
Yet it is unclear whether Mr. Moallem and Mr. Khatib have the full backing of their own sides for talks. Mr. Khatib’s group, the National Coalition of Syrian Revolution and Opposition Forces, insists that it will speak only with members of Mr. Assad’s government without “blood on their hands.” Lakhdar Brahimi, the special Syria peace envoy representing the United Nations and the Arab League, has appeared to support Mr. Khatib’s position, calling on the government to send an “acceptable delegation.”
But on Wednesday, Mr. Lavrov said that the two sides should not impose preconditions or “say that I am going to talk to this person but not that one.” He was speaking after a meeting of the Russia-Arab Forum from which the representatives of the rebels’ main Arab backers, Saudi Arabia and Qatar, were absent.
In Syria on Wednesday, rebel shells appeared to reach new areas in Damascus, activists and witnesses reported. Goran Tomasevic, a photographer for The Associated Press who has recently produced images of fighting in the Damascus suburbs as one of the few foreign journalists with rebel fighters there, described a deadly stalemate between two well-coordinated fighting forces that he said was reminiscent of wars that gutted cities like Sarajevo and Stalingrad.
“Rebel fighters in Damascus are disciplined, skilled and brave,” he wrote in an account published on Wednesday. “In a month on the front-line, I saw them defend a swath of suburbs in the Syrian capital, mount complex mass attacks, manage logistics, treat their wounded.”
But, he added, “as constant, punishingly accurate, mortar, tank and sniper fire attested,” government soldiers, often fighting at close range, “are also well drilled, courageous — and much better armed.”
Both state media and opposition activists reported on Wednesday that mortar rounds had hit the Tishreen sports stadium in the downtown neighborhood of Baramkeh. The state news agency, SANA, said the explosion killed an athlete from the Homs-based Al Wathba soccer team as he was practicing.
Government forces hit a rebel command center in a suburb east of the capital on Wednesday, injuring a founder of the Liwaa al-Islam brigade, Sheik Zahran Alloush, the brigade said in a statement.
It said the attack “won’t stop or weaken the will of the battalion” and asked for “God’s help to reach the criminals for retribution.”
Hania Mourtada and Hwaida Saad contributed reporting.