Kano: Nigeria has arrested 200 people, mostly Chadian "mercenaries," after last week`s attacks in the northern main city of Kano, a police source said on Thursday, as a fresh blast struck the same area.

The explosion at a Kano bus terminal caused no casualties and its causes were not immediately clear, but it forced the area to be evacuated, the Army and police said.
The deadliest violence to hit Kano came last Friday, when coordinated gun and bomb attacks, claimed by the Islamist group Boko Haram, killed at least 185 in the primarily Muslim city.
"Many arrests have been made since the attacks," the police source said on condition of anonymity, referring to the Friday assaults.
"We have arrested around 200 attackers and 80 percent of them are Chadians. They came in as mercenaries."
There were indications the Chadians had been paid to participate in the recent attacks attributed to Boko Haram, the source added. Boko Haram has been blamed for scores of other attacks in Nigeria, mainly in the north, and security forces have long suspected it of smuggling arms into the country through the porous northeastern borders with Chad and Niger.
A UN report on regional security released yesterday said there was evidence suggesting the Nigerian group had Chadian members who had received training from al Qaeda`s north Africa affiliate.
But a Nigeria specialist with the International Crisis Group (ICG) said it was unlikely the sect had such a high number of foreigners in its ranks.
"I was shocked to hear that myself. Personally, I don`t believe it," said Kunle Amuwo of the ICG, when asked about the police claim that most of those arrested had come from Chad.
"We know some foreigners have been implicated and continue to be implicated, but that number is huge," he said, adding that, based on his research in the region, he believes most Boko Haram members are dejected Nigerian youths. Nigerian authorities have come under immense pressure over the spiralling violence blamed on the Islamists and have in the past been accused of rounding up innocent civilians in response to attacks.
"Following previous attacks by Boko Haram, the security forces have often resorted to dragnet arrests, rather than arresting people on the basis of a reasonable suspicion that they committed an offence," Amnesty International said earlier this week.
There was no immediate evidence linking Thursday`s blast at the bus terminal in Kano to the Islamist group.
"We just had an explosion, nobody can confirm the cause. No loss of life or injuries was recorded. The area is being evacuated," a police spokesman in the city, Magaji Majia, said.
A witness however claimed two people were injured.
Locals say the area, known as New Road, holds a bus terminal for people travelling to the country`s eastern region.
PTI