Thousands of opponents of Egypt’s Muslim Brotherhood clashed with supporters of the Islamist group near its headquarters in Cairo yesterday, and at least 40 people were wounded, authorities said.

Columns of riot police fired tear gas as the rival groups tussled in the streets around the Brotherhood headquarters. Protesters hurled Molotov cocktails and stones, a witness said.

Earlier in the day, Brotherhood supporters who arrived in the vicinity on buses were showered with stones from the protesters and threw stones back.

About 40 people were wounded in the fighting, Health Ministry official Khaled al-Khatib told state news agency Mena. They included a former presidential candidate, liberal Khaled Ali, who was injured in the shoulder, Mena said.

State TV showed large plumes of black smoke rising from the surrounding streets which it said came from buses set on fire. The buses belonged to the Brotherhood, an official from the group told Mena, who said protesters had set them alight.

The Brotherhood, of which President Mohamed Morsi is a leading member, had vowed on Thursday to defend the building.

The Interior Ministry urged “revolutionary and political forces” to remain peaceful during the protests, saying in a statement it had sent riot police to protect property.

“The Interior Ministry has sent riot police forces to the headquarters of the Muslim Brotherhood to protect public and private property,” it said in a statement.

Anti-Brotherhood protesters clashed with police outside the building this week, the latest burst of unrest in a nation still struggling to restore law and order since its 2011 uprising. (Reuters)