CAIRO – Egypt’s government and protesters edged closer to violent confrontation Wednesday as demonstrators escalated their tactics and the vice president warned sharply of a coup if the unrest continued, saying protests must end or “the dark bats of the night” would emerge to terrorize the nation.

Labor unrest continued to plague the nation for a second day, threatening to merge the political goals of the opposition with the more focused economic issues that have long plagued Egypt. And violence spread to a normally peaceful desert oasis 500 miles southwest of Cairo, where police killed four people.

Protesters in Tahrir Square, re-energized by massive crowds Tuesday after turnout began to flag on Monday, promised the biggest demonstrations yet on Friday, this time nationwide as well as in multiple locations in Cairo. On Wednesday, they defied the Egyptian army by occupying the street in front of parliament, creating a second front in downtown Cairo.

Egyptian Vice President Omar Suleiman, in comments to Egyptian newspaper editors published Wednesday, warned sharply that demonstrations could not continue. Suleiman, who until now has presented himself as a soft-spoken voice of reason in discussions with opposition leaders, sounded rattled as he warned of tougher measures.

The protests are “very dangerous for society and we can’t put up with this at all,” he said. “We don’t want to deal with Egyptian society with police tools.”

He said he foresaw “the dark bats of the night emerging to terrorize the people” if the situation is not resolved. If protests against President Hosni Mubarak’s leadership continued, he said, the likelihood is that “a coup happens, which would mean uncalculated and hasty steps, including lots of irrationalities.”

A coup could come from within the regime, the army, the police or intelligence services — which he used to lead — or the opposition, Suleiman warned.

The army has taken over security from the police, but has focused on the protests, not police work. It has been highly praised by the opposition since it moved into Cairo and other urban areas, but Wednesday that relationship seemed to change as the Muslim Brotherhood, the largest opposition group, accused the army of arresting and torturing protesters headed to Tahrir Square.

On Wednesday, about 500 protesters blocked the street in front of parliament, some of them having camped there overnight after Tuesday’s massive gathering in Tahrir Square, four blocks away, spilled over. The government has promised not to forcibly remove demonstrators from the central plaza, but the occupation of new territory increased pressure on the army to act.

In New Valley, a western province, security forces reported that the first sizable anti-Mubarak gathering in the region Tuesday and Wednesday resulted in four people being killed and several wounded by gunshots in clashes with police.

Protesters in the city of Port Said set the City Hall building on fire after saying the city’s governor ignored their complaints for subsidized housing facilities.