Sana’a: Thousands of supporters of rebels pressing the government to step down gathered in the Yemeni capital on Friday as a presidential team was in the northern Al Houthi stronghold for crisis talks.

The rally came on the final day of an ultimatum set by the Shiite Zaidi rebel commander, Abdul Malek Al Houthi.

He urged supporters to gather for weekly prayers on the road leading to Sana’a International Airport in the north of the capital.

The protest marks the start of the “second phase of the peaceful revolutionary escalation” through “legitimate means”, according to Al Houthi.

Thousands poured into the gathering site from Sana’a’s outskirts, an AFP correspondent reported, while security measures remained unchanged across the capital.

Thousands of armed rebels, also known as Ansarullah or Al Houthis, have strengthened their positions around Sana’a as they press their campaign to force the government, which they accuse of corruption, to step down.

The protesters also want a steep increase in petrol prices to be revoked.

The movement has raised fears of a new wave of violence in impoverished Yemen, which is in political transition at a time of an Al Qaida insurgency and southern separatist demands.

Bracing for an escalation at the weekly prayers, President Abd Rabbo Mansour Hadi on Thursday urged the armed forces to “raise their level of vigilance”.

In response, the rebel commander vowed in a speech: “We will not remain with our arms folded if the armed forces attacked protesters.”

Meanwhile, a presidential delegation was holding talks with the Al Houthi commander in his northern stronghold of Saada to convince his group to join a national unity government.

Al Houthi said late on Thursday that the delegation had “shown understanding for some of our demands” but negotiations and protests would continue.

The Zaidi rebels strongly oppose the government’s plans for a six-region federation, demanding a single region for the northern highlands and a greater share of power in the federal government. They control Saada province in the far north and parts of several neighbouring provinces.

Rebels reached the outskirts of Sana’a in July after seizing Amran to its north, although they later agreed to withdraw.

The Al Houthis have been fighting an on-off conflict with government troops in the northern mountains for the past decade, but analysts warn that their bid for more power in a promised new federal Yemen is potentially explosive.

The Zaidi Shiites, a minority in mainly Sunni Yemen, form the majority in the northern highlands, including the Sana’a region.