Mali Monday started three days of national mourning for the victims of the jihadist siege at a luxury hotel that left 19 people dead in the capital Bamako, with neighbouring Senegal, Mauritania and Guinea joining in a show of solidarity.
The investigation was "following several lines" with no certainty about the number and nationality of the perpetrators of the attacks, which have been claimed by two separate jihadist groups.
Gunmen went on the rampage at the Radisson Blu hotel from early morning on Friday, shooting in the corridors and taking 170 guests and staff hostage.
The assault, which ended when Malian and international troops stormed the building, left 19 people dead, including 14 foreigners, as well as two attackers, according to a "definitive" report by the government.
The victims included six Russians, three Chinese, two Belgians, an American, an Israeli, a Senegalese and a member of the Malian special forces.
The UN peacekeeping force in Mali, MINUSMA, however spoke of 22 fatalities, including two attackers.
Senegal's President Macky Sall visited Bamako Sunday to show national solidarity and the support of the West African regional bloc ECOWAS which he chairs.
"Mali will never be alone in this fight, we are all committed because we are all involved," he said, announcing that Mali's neighbours Senegal, Mauritania and Guinea would also observe three days of mourning.
Al-Murabitoun group, an Al-Qaeda affiliate led by notorious one-eyed Algerian militant Mokhtar Belmokhtar, has claimed responsibility for the attack.
The group said Sunday there were only two attackers and suggested they were Malian.
In a recording broadcast by Al-Jazeera, a spokesman identified them as Abdelhakim al-Ansari and Moez al-Ansari, with the term "al-Ansari" indicating they were indigenous jihadists.
A jihadist group from central Mali, the Macina Liberation Front (LWF), however claimed the attack in a statement sent to AFP Sunday, saying it was carried out by a squad of five, including "three who came out safe and sound".
A Malian security source told AFP that the authorities were "actively pursuing" at least three people over the attack in the former French colony.
Another informed source spoke of "three or four accomplices" believed to have aided the "foreign" gunmen who attacked the hotel frequented by businessmen, diplomats and other expatriates.
"Everything points to two foreigners," the source said.
The same source said "it is likely that the two foreigners went from bar to bar so they would not be noticed, and at dawn (Friday), the Malians could have guided them in the attack on the Radisson".
Investigators were combing through the hotel and had recovered several items inside which could help the enquiry, a police source said.
"We are following several lines, but we won't be making a statement," the police source told AFP.
Guinean singer Sekouba Bambino Diabate, who was among the survivors, told AFP the gunmen spoke English among themselves.
French Defence Minister Jean-Yves Le Drian has said Belmokhtar, one of the world's most wanted men, was indeed "likely" the brains behind the assault.
"He is circulating," he said of the Algerian jihadist believed to be in Libya.
Despite the state of emergency imposed since late Friday, residents of Bamako were trying to return to normal life.
Security remained high at the major hotels. It was more discreet, though tighter than usual, at public buildings and banks.
Many Malians were on Sunday determined to resume their usual lives, with noisy wedding processions in the capital, but some cautioned against too quick a return to routine.
"People are not being vigilant. We forget. I don't know whether it's because of the problems of daily life, but people just aren't being careful here," said hotel worker Daouda Sissoko.
Others are concerned that Friday's attack will have more economic repercussions for a country still recovering from a 2012-13 civil war.
Mali has been torn apart by unrest since the north fell under the control of jihadist groups linked to Al-Qaeda in 2012.
The Islamists were largely ousted by a French-led military operation launched the following year, but large swathes of Mali remain lawless.
France has more than 1,000 troops in its former colony, a key battleground of the Barkhane counter-terror mission spanning five countries in Africa's restive Sahel region.
Le Drian said on Sunday his country's efforts in Mali have not been in vain.
"Democracy has returned, terrorism has been virtually eradicated, or at least pushed back to northern Mali and the Barkhane force is doing exceptional work," he told Europe 1 radio.