Chad's former dictator Hissene Habre appeared in court Tuesday after his arrest in Senegal by investigators seeking to put him on trial for crimes against humanity.

Habre -- once dubbed "Africa's Pinochet" -- also faces accusations of war crimes and torture during his eight years in power in Chad, where rights groups say 40,000 people were killed under his rule.

Senegalese authorities detained former Chadian dictator Hissene Habre on on Sunday, the first step towards a trial on charges of crimes against humanity that is seen by many as a milestone for African justice.

The man once dubbed "Africa's Pinochet" also stands accused of war crimes and torture during his eight years in power in Chad, where rights groups say that some 40,000 people were killed under his rule.

Niger's president said Monday that attackers who bombed an army base and French-run uranium mine, leaving 38 people dead, entered his country from southern Libya, where he warned further attacks were being planned on Chad.

"For Niger in particular, the main threat has moved from the Malian border to the Libyan border. I confirm in effect that the enemy who attacked us... comes from the (Libyan) south, where another attack is being prepared against Chad," said President Mahamadou Issoufou.

A foiled coup attempt in Chad has left several people dead while a number of others have been arrested in connection with what the government described as a "destabilization plot" in the landlocked central African country, police sources said Thursday.

A shootout broke out on the outskirts of the capital N'Djamena on Wednesday when security forces came to arrest the alleged conspirators, leaving "several dead and around 15 injured", a police source said on condition of anonymity.

Chad has arrested a group of people trying to carry out a "destabilization plot," as police and opposition sources said one of the detainees was an opposition lawmaker.

"A small group of ill-intentioned individuals attempted to carry out a destabilization plot against the institutions of the republic," the government said in a statement Wednesday, without indicating how many people were involved.

A suicide bomber killed at least three Chadian soldiers in Mali Friday, military sources said, in a deadly demonstration of the troubled nation's ongoing security crisis days after France began withdrawing its troops.

The soldiers were shopping in the northern city of Kidal when an Islamist bomber struck, according to Malian and Chadian sources who gave a provisional toll of three soldiers killed and four wounded.

Chad's 2,000-strong contingent in Mali, which has played a leading part in the fight against jihadist militants, on Saturday officially joined the regional African force deployed there.

"As of today, our Chadian brothers who are fighting to liberate Mali are joining AFISMA," Ivorian army chief Soumaila Bakayoko, whose country currently chairs the regional bloc ECOWAS, told reporters.

Britain said Sunday that the reported killing of Islamist militant Mokhtar Belmokhtar would be a blow to terrorism in North Africa but would not represent the end of Mali's troubles.

Chad said its troops in northern Mali had killed Belmokhtar, the one-eyed Islamist leader who masterminded an assault on an Algerian gas plant that left 37 foreign hostages dead in January.

Chad has said its troops in northern Mali killed the one-eyed Islamist leader who masterminded an assault on an Algerian gas plant that left 37 foreign hostages dead in January.

The Chadian army, whose troops have been at the forefront of the hunt for Al-Qaida-linked fighters hiding in northern Mali, said Mokhtar Belmokhtar was killed during an operation in the Ifogha mountains on Saturday.

Algerian officers have found a weapon that belongs to a top al-Qaida operative reportedly killed in Mali and examined a body but are still unable to confirm it is his, a daily said on Saturday.

El Khabar's report comes a day after Chadian President Idriss Deby Itno said that Abdelhamid Abu Zeid was killed in deadly fighting between Chadian troops and Islamist fighters on February 22 in northern Mali.