U.N. chief Ban Ki-moon vowed Tuesday to help the people of Africa's poor and conflict-scarred Sahel as he began a regional tour in Mali overshadowed by the murder of two French journalists.

Ban, World Bank chief Jim Yong Kim and top officials from the African Union, African Development Bank and European Union met Mali's president and key government ministers at the start of a three-day trip that will also take in Niger, Burkina Faso and Chad.

Talks on a protracted row over Iran's nuclear ambitions resume this week in Geneva, with Tehran announcing a visit by the U.N. atomic watchdog chief to try to clinch a deal.

The so-called P5+1 group of major powers will meet Iran's nuclear team on Thursday and Friday for the latest round of negotiations revived after the election of Iranian President Hassan Rouhani, a reputed moderate.

The European Court of Human Rights on Tuesday sentenced Turkey over a case of police torture dating back to 1999, imposing a fine of 20,000 euros ($27,000).

Mesut Deniz, a 38-year-old Turk currently serving a prison sentence, said he was given electric shocks, hanged by his arms, had his genitals twisted and subjected to other forms of torture after his arrest.

A would-be migrant died Tuesday when he fell while trying with 150 others to scale the border fence separating Morocco from Spain's north African territory of Melilla, Moroccan officials said.

The incident, in which another four people were injured, comes a day after 80-100 migrants succeeded in getting across by charging the seven-meter (23-foot) high fence at a point where it had not yet been reinforced.

Suspected militants killed five policemen in an ambush in India's northeast on Tuesday, officials said, a day after separatists from the same group killed seven villagers.

Members of the outlawed Garo National Liberation Army (GNLA) attacked a police vehicle in the northeastern state of Meghalaya as officers were transferring one of their fellow rebels, who is on trial.

Nigeria's army said Tuesday it had shot dead seven suspected Boko Haram fighters during a raid in a northeastern area where the Islamist rebels have killed dozens in the last week.

The Bama area in Borno state, where the latest fighting occurred, has become a flashpoint in Boko Haram's four-year insurgency.

Scores of migrants entered Spain's north African territory of Melilla Tuesday after storming a border fence, which authorities are busy topping with barbed wire to discourage such assaults, a local official said.

"Between 80 and 100" migrants managed to enter Melilla after charging the seven-meter (23-foot) high fence at dawn at a point where it had not yet been reinforced, the local government spokesman said.

Turkey resumed talks to gain entry into the European Union after a 40-month freeze Tuesday, with both sides hailing a potential "turning point" in Ankara's stalled bid to join the EU club.

"This is only a beginning," said Turkey's EU Affairs Minister Egemen Bagis after officially opening negotiations on chapter 22, one of 35 sets of rules and standards that EU candidates must satisfy before joining the 28-member bloc.

Gunmen in Pakistan's financial metropolis Karachi shot dead five Sunni Muslims a day after six minority Shiites were killed in the same city, officials said.

Police said the five belonged to the conservative Deobandi movement and were either members of sympathizers of banned extremist outfits.

Nigeria's Boko Haram Islamists could be classed as war criminals, the United Nations human rights office said Tuesday, as it condemned a bloody attack on a wedding convoy.

"Members of Boko Haram and other groups and entities, if judged to have committed widespread or systematic attacks against a civilian population ... (could be) guilty of crimes against humanity," said Cecile Pouilly, spokeswoman for the U.N. High Commissioner for Human Rights.