Chadian police fired tear gas Saturday to disperse protesters, who defied a ban to demonstrate against the junta that took power after longtime ruler Idriss Deby Itno died fighting rebels.

Chad will bury veteran ruler Idriss Deby Itno on Friday as concerns mount over the loss of a lynchpin in the fight against jihadism in the Sahel and uncertainty over the country's democratic future.

Some 2,000 troops from regional military powerhouse Chad headed to neighboring Niger on Wednesday, where Boko Haram insurgents inflicted heavy losses in the town of Bosso last week, a military source said.

Chad is a leading member of a multi-national force fighting the Nigeria-based Islamists who have extended their attacks to neighboring countries from their base in northern Nigeria.

Gunmen killed a Chadian army officer serving in a joint unit patrolling Sudan's border with Chad in the war-torn region of Darfur, the Sudanese military said Thursday.

The joint force has operated in Darfur since 2010, seven years after ethnic minority insurgents in the western region rebelled against the Arab-dominated Khartoum government.

Chad's opposition successfully locked down the capital and other cities Wednesday, closing markets, shops and slowing traffic in a countrywide protest at President Idriss Deby Itno's bid for a fresh fifth term in office.

The protest emptied N'Djamena's two big markets of shoppers and school classrooms remained empty following the call for a nationwide shutdown under the slogan "That's Enough".

Riot police violently shut down a protest on Monday by hundreds of young Chadians in the capital N'Djamena, after photographs of a girl who had allegedly been brutally gang-raped spread on social media.

One protester was reported to have been shot dead as police moved to disperse the demo with tear gas, a fellow demonstrator told AFP on condition of anonymity.

Chad's ex-dictator Hissene Habre had the "power of life and death" over his people, a lawyer for victims of atrocities carried out during his 1980s reign said Monday at his war crimes trial in Senegal.

Habre who was president of the semi-desert central African country from 1982-1990, is charged with war crimes, crimes against humanity and torture -- the first time a despot from one African country has been called to account by another.

Chad's parliament has decided to prolong a state of emergency in the southern Lake Chad region, prey to bomb attacks by the Nigerian Islamists of Boko Haram, a parliamentary source said Thursday.

The resolution was unanimously passed on Wednesday night by 147 members of parliament and will extend the special powers given to regional authorities until March 22, 2016.

A twin suicide bombing by women attackers in the flashpoint area of Lake Chad on Sunday killed two people and wounded 14 others, a security source in the Chadian capital N'Djamena said.

"The two women suicide bombers and two civilians died in the blast," the source told AFP on condition of anonymity, adding that "14 others were injured" in the attack blamed on Nigeria's Boko Haram group on Ngouboua village near the Nigerian border.

Boko Haram Islamists attacked Chadian soldiers on Tuesday, killing 11 and wounding 13, a Chadian security source said, in the latest deadly raid by the militants despite a regional offensive against them.

The source said 17 Boko Haram fighters also died in the fighting following the pre-dawn strike near the Nigerian border and Lake Chad.