All it took was a few words in a Bahrain school yard.
Suddenly, Shiite and Sunni girls were scuffling, then parents rushed to the scene and finally police and parliament members arrived to try to separate an angry faceoff between loyalists praising the Sunni rulers and Shiites cursing their names.
The fast-moving melee Thursday at a girls' high school was just a passing brush fire in the context of Bahrain's nearly monthlong political implosion, which has laid bare the divide between the majority Shiites and the Sunni ruling class.
But it carried a vivid lesson about the huge challenges to ever put back the pieces in the strategic Gulf kingdom, which hosts the U.S. Navy's 5th Fleet. Bahrain's uprising _ now longer than the Egyptian revolt that inspired it _ appears to be moving into a long-haul mode with short-fuse emotions.
"The government wants dialogue?" screamed Shiite attorney Abdullah al-Shamlawi as he searched for his daughter at the Saar Secondary School about six miles (10 kilometers) west of the capital Manama.
"This is the dialogue that they want? This is Taliban dialogue."
As resolve deepens among the Shiite-led protesters _ who mark their first month Monday _ so does the backlash from hard-line Sunni factions that fear their privileges and way of life could hang in the balance.
Sunni groups have organized their own vigilante protection squads and peppered the web with threats and messages mocking calls for unity. In one video clip on YouTube, a former Sunni parliament member, Sheik Khaled Mohammed, calls Shiite protesters "monkeys" who are putting the country at peril.
It's far more than just nasty local venom, though. Bahrain figures strongly into larger regional questions, including whether other Sunni rulers in the Gulf will try to prop up Bahrain's embattled monarchy and how much Washington could intervene if the instability threatens the 5th Fleet's presence and its role as the Pentagon's front-line force against Iran.
"Bahrain is already bitterly divided," said Ibrahim Sharif, head of the Waad Society, one several mostly Shiite opposition groups. "The country cannot afford to be pulled apart any more. We must unite. We cannot wait."
The recriminations and propaganda flying about, however, say otherwise.
Apparent Sunni activists have sent out dozens of text messages and Twitter posts in the past week portraying the Shiites as "traitors" loyal to Shiite powerhouse Iran or Lebanon's Hezbollah. Stern warnings also have come about Friday's planned march near the royal palace after some prominent opposition leaders called for dissolving the monarchy that has ruled for two centuries.
"Shiites are not welcome" near the palace, said one Twitter message. Other claimed that Bahrain Sunnis would fight to the death to protect the king.
Although the chants about Sunni-Shiite unity are fixtures of Bahrain's daily protest marches, there's also smear campaigns under way by presumed Shiite organizers.
A text message circulating Thursday commented on a video last week that purported to show pro-government thugs in Bahrain waving clubs and carrying an al-Qaida banner. "They are terrorists," said text message by Mohammed Abdullah, a Shiite opposition supporter and restaurant owner.
Other postings on Facebook and elsewhere harshly denounce the government's policy of giving citizenship and jobs _ including police and military posts _ to Sunnis from other Arab countries and South Asia, calling them part of a "mercenary" force involved in clashes that have claimed seven lives.
"The government who wants a sectarian war more than a national dialogue," said Mohammed Habib al-Muqdad, a Shiite activist who was among 25 Shiites accused of trying to topple the ruling system. The trial has been dropped.
The chaos at the Saar school embodies the hair-trigger atmosphere.
Witnesses told The Associated Press it began with rival demonstrations during morning break: mostly Shiites students calling for political reforms and Sunni girls supporting the rulers. A fight broke out and the principal tried to isolate the Sunni group inside the school.
Soon, parents streamed toward the school with some fathers carrying sticks and clubs, said lawmaker Mohammed Majeed, whose daughter was slightly injured. Police moved in as hundreds of people squared off at the school.
When Shiite students heard the Yemeni accent of one policemen, they jeered.
"Go back! We don't want you here," they yelled.
A statement Thursday by political figures from both sides appealed for the country not to slip into a sectarian crisis. A day earlier, a group of 25 Sunni clerics also condemned efforts to "foment sectarian tensions."
"The events that took place in the kingdom ... have left a strong impact on members of the two communities who belong to one nation and religion," the clerics' statement said.
It underscores the vastly different perspectives pulling at Bahrain _ and, in many ways, the wider region.
Many of Bahrain's Shiites _ about 70 percent of the population _ see themselves trapped in a permanent underclass.
They are effectively blackballed from top government or security posts and complain that voting districts are gerrymandered to prevent a Shiite majority in the 40-seat parliament, where the main Shiite bloc took 18 seats in elections last year.
But perhaps the most gnawing grievance is the Sunni naturalization policies, which seek to offset the lopsided Shiite demographic advantage and bulk up the ranks of loyalists. Opposition groups estimate tens of thousands of Sunnis from across the Arab world and South Asia have been brought to Bahrain in recent years.
On Wednesday, thousands of Shiites marched outside the immigration office in the capital Manama to decry the "political naturalizations" and demand a mass expulsion.
The Shiite-led protests also reflect growing calls to oust Bahrain's King Hamad bin Isa Al Khalifa and the rest of the ruling dynasty.
"Hamad must go!" shouted Shiite crowds after the melee at the school.
This doesn't just raise the stakes of Bahrain's showdown. It resonates in a very direct way the pro-Western kings and sheiks who hold power across the Gulf, where protests have so far flared in Oman, Kuwait and even in the political choke-hold atmosphere in Saudi Arabia.
Gulf leaders see any crack in their fraternity as a potential threat to all. They also, in varying degrees, view Bahrain as a crucial stand against Iranian influence _ even though there is no particular evidence of Tehran links to Shiites political groups in Bahrain.
"It's not a stretch to say that many Sunnis see any political gains by Bahrain's Shiites as opening the door wider for the big Shiite player, Iran," said Toby Jones, an expert on Bahrain at Rutgers University, in a recent interview. "It doesn't matter if can be supported by fact. The perception is there and that is what counts."