Supporters of Lebanon's Hezbollah blocked main roads in Beirut with burning barricades on Wednesday, paralysing the city and deepening the pro-Iranian group's conflict with the US-backed government.
They set ablaze old cars and tyres to block the main road to Beirut's international airport, where air traffic was suspended because of a strike by staff taking part in a labour union protest to demand higher wages.
The Hezbollah-led opposition has backed the strike. Activists loyal to Hezbollah, a political group with a guerrilla army and backing from Iran and Syria, also blocked routes to Beirut's main commercial district and the usually busy sea port.
The scenes were reminiscent of an anti-government protest last year that led to some of Lebanon's worst internal strife since its 1975-90 civil war. A stun grenade exploded in Beirut, slightly wounding one person, a security source said.
In Lebanon's deepest political crisis since the civil war, Hezbollah has been leading a campaign against Prime Minister Fouad Siniora's government since November 2006.
The standoff, which has left Lebanon without a president for five months, reflects a broader power struggle between the foreign backers of the rival camps. The government is supported by Arab states including Saudi Arabia, whose ties with Syria have been poisoned by the Lebanon crisis.
Tension between the government and Hezbollah escalated sharply on Tuesday. The cabinet accused the group of violating Lebanon's sovereignty by operating its own communications network and installing spy cameras at the airport.
It also removed the head of Beirut airport security in another challenge to Hezbollah.
The group said the communications network was part of its security apparatus and had played a major role in its war with Israel in 2006.
Provoked by the government's move, Hezbollah was "flexing its muscles" in the streets, said Oussama Safa, director of the Lebanese Center for Policy Studies. "The heat has been turned up," he said, adding that there was scope for violence.
"But it's probably not going to unfold into war. A confrontation is not winnable.
"Things could get very ugly, but I don't think they will spread out of hand," added Paul Salem, director of the Carnegie Middle East Center in Beirut. "Everyone is armed and angry."
The rival camps have traded accusations that they have been arming and training their followers in case of conflict.
Hezbollah was the only Lebanese faction allowed to keep its weapons after the civil war to fight Israeli forces occupying the south. Israel withdrew in 2000 and the fate of Hezbollah's weapons is at the heart of the political crisis.
A UN Security Council resolution that ended the 2006 war between Hezbollah and Israel bans the group from rearming and rebuilding its military infrastructure in south Lebanon.
Governing coalition leaders allege Hezbollah is spying on the airport to monitor their movements. Eight members of the anti-Syrian coalition have been assassinated since 2005. - Reuters