Seven soldiers were killed and several others wounded or missing after their patrol was ambushed in northern Burkina Faso, security sources said Thursday.

Burkina Faso's security forces allegedly executed 31 unarmed detainees in the northern town of Djibo, Human Rights Watch said Monday, calling for an immediate investigation.

German Chancellor Angela Merkel on Wednesday promised aid to strengthen security in jihadist-hit Burkina Faso after arriving in the West African country.

Merkel, who also attended a G5 meeting of Sahel country leaders, is due travel on to Mali and Niger.

Al-Qaida in the Islamic Maghreb (AQIM) Monday named three gunmen behind a deadly attack on a luxury Burkina Faso hotel that has highlighted the growing reach of jihadist groups in west Africa, as French police joined in the probe.

Burkinabe troops fanned out across the capital, Ouagadougou, with security stepped up at key sites as visiting Benin President Thomas Boni Yayi pledged that west African nations would fight back against a mounting terrorist threat.

At least 26 people, many of them foreigners, were killed in an attack overnight on a top hotel in the capital of Burkina Faso, the latest country to be drawn into a regional jihadist battle against the West and its allies.

A total of 126 people were freed, 33 of them wounded, from the four-star Splendid hotel after security forces retook the facility and nearby Cappuccino restaurant on Saturday over 12 hours after the attack began, Interior Minister Simon Compaore told Agence France Presse.

Roch Marc Christian Kabore has won Burkina Faso's presidential election, official results showed, after a year of turmoil that saw the west African country's former leader deposed and the military try to seize power.

Kabore, who governed under former strongman Blaise Compaore before turning his back on the old regime, won the vote in the first round with 53.49 percent of ballots, the electoral commission said late Monday.

Roch Marc Christian Kabore, an affable and strongly built banker, late on Monday was named the president of Burkina Faso, the first new leader of the west African country in almost three decades.

Seen as a consensus figure by some and an opportunist by others, he once governed under ousted strongman Blaise Compaore but turned his back on the old regime before it cracked under the pressure of a massive popular revolt.

General Gilbert Diendere, the leader of Burkina Faso's short-lived coup, was in police custody on Thursday after handing himself in, a security source told AFP.

Diendere, who had said several times that he was willing to face justice following the September 17 putsch, was at the Paspanga police base near the center of the capital Ouagadougou on Thursday afternoon.

Burkina troops were on Wednesday hunting the remaining guards behind a coup a day after storming their barracks as the EU hailed the end of the unrest and urged speedy elections.

Tuesday night's raid saw troops in the capital Ouagadougou firing heavy weaponry at the barracks of the elite presidential guard (RSP) who staged an abortive coup on September 17.

Heavy firing erupted Tuesday at the barracks of an elite military unit which staged a short-lived coup in Burkina Faso as their leader asked his troops to lay down their arms to "avoid a bloodbath".

The Burkinabe military meanwhile warned it was giving the failed putschists "yet another chance" to give up their weapons in line with a peace deal mediated by regional powers.