KHARTOUM — Sudanese security forces fired tear gas at a landmark mosque in the capital Khartoum on Friday after the Muslim noon prayers, witnesses and the main opposition Umma party said, and several worshippers were injured or overcome by fumes.

The attack came as hundreds of worshippers tried to march from the Al-Sayed Abd Al-Rahman Al-Mahdi mosque, one of the capital's main mosques, as part of near daily protests against President Omar Al-Bashir's 30 years in office.

Sudan has been rocked by the protests which began on Dec. 19 after the government tried to raise bread prices. Rights groups say at least 45 people have been killed in the protests, while the government puts the death toll at 31, including two members of security forces.

The Umma party of former Prime Minister Sadiq Al-Mahdi said in a statement that security forces attacked worshippers soon after noon prayers, firing tear gas "extensively" into the mosque courtyard.

"Firing at the mosque and the vehicle of Imam Sadiq Al-Mahdi, beating worshippers, pointing guns in their faces and besieging the mosque... resulted in the wounding of several worshippers, while others suffered suffocation," the statement said.

It accused Bashir's government of no longer abiding by the Sudanese people's values as it sought to cling to power. A police spokesman could not immediately be reached for comment despite repeated attempts to do so.

Bashir has blamed the protests on foreign "agents" and challenged his rivals to seek power through the ballot box. He has shown no sign that he is prepared to concede any power.

Protests also broke out in other parts of Khartoum, where demonstrators blocked roads with burning tires and tree branches. Security forces dispersed the protests with tear gas but there were no reports of injuries.

In eastern Sudan, hundreds marched in Khashm Al-Qirba, the hometown of a school teacher who died in detention last week after he was arrested for participating in protests.

Demonstrators chanted: "With our souls, with our blood, we redeem you, teacher." Security forces did not intervene.

An investigator on Thursday confirmed that teacher Ahmed Al-Kheir, 36, had died from wounds sustained while in detention after he was arrested last week by security agents.

Kheir, a member of Sudan's Islamist Popular Congress Party, was detained for allegedly organizing anti-government protests, a relative said.

On Friday, crowds of protesters in Khashm Al-Griba staged a rally after the weekly Muslim prayers to protest his death. "We will give our blood to keep you alive," chanted the protesters, who emerged from several mosques after prayers and held a march.

Kheir was arrested by agents of the country's powerful National Intelligence and Security Service (NISS), his uncle Ahmed Abdelwahad said as the family took his body from a mortuary.

"We have asked the chief of NISS in Kassala to bring the security agents who interrogated Kheir in Khashm Al-Girba," Amer Ibrahim, the head of an investigative committee at the prosecutor's office, told reporters on Thursday, indicating he had died in detention. "The man had wounds on the back, legs and other parts of his body that led to his death," Ibrahim said. — Agencies