By Joe Brock
ABUJA (Reuters) - At least seven people were killed in the Nigerian capital Abuja on Friday in what security forces said was a shootout with Islamists, but witnesses at a hospital said was an attack on unarmed squatters.
The incident happened in a building near a sprawling, walled-off residential compound for lawmakers.
Nigeria's SSS intelligence service said its forces had been searching an area behind the Apo Legislative Quarters for weapons after a tip-off from arrested members of the Islamist militant group Boko Haram when they came under fire and shot back. It mentioned injuries but no deaths.
If Boko Haram, which wants to impose sharia or Islamic law in northern Nigeria, did open fire, it would be the first clash involving Islamists in the capital this year.
A doctor in a hospital morgue, who declined to be named because he was not authorized to speak, said seven people had been killed in the incident. A Reuters reporter saw a police truck dump three bodies then drive off, leaving a trail of blood.
An ambulance deposited another body, with bandages wrapped around the bloodied torso. There was no security presence at the hospital, as might have been expected if there had been Boko Haram suspects among the wounded.
Six witnesses, including two people injured by bullets, told Reuters the building was a house owned by a military man that had been occupied by about 100 squatters who were refusing to leave. Security forces raided it and opened fire on the squatters, they said.
Boko Haram has been responsible for hundreds of killings this year, although Nigerian forces are also often accused of executing suspects then labeling them Boko Haram.
A statement from the State Security Services (SSS) said: "No sooner had the team commenced digging for the arms than they came under heavy gunfire attack by other Boko Haram elements.
"Some persons were injured and 12 others have been arrested in connection with the incident."
Witnesses disputed the SSS account. A 28-year-old shoe hawker in torn clothes, who gave his name only as Mohammed for fear of reprisals and nursed a bloody bandages around both legs, said he was one of the squatters.
He said the owner had come on Wednesday and told them to leave, but they had refused because they were paying a security guard to be allowed to stay there.
On Thursday the security guard had left, then at around midnight, five pick-up trucks arrived carrying armed personnel.
"They began firing. It was crazy," Mohammed said. "We were running helter skelter and bullets were flying."
Five other witnesses gave similar accounts, but two security sources said they believed the SSS had gone to the building to identify Boko Haram suspects and recover arms.
Boko Haram and a patchwork of smaller Islamist groups are seen as the gravest security threat to Africa's top oil producer. Although Boko Haram concentrates its attacks in the northeast, hundreds of miles away from the oil fields in the south, its small presence in the political capital worries officials.
The last known Islamist attack in the capital was last November, when gunmen stormed a special anti-robbery police barracks and freed 30 prisoners, killing two policemen. That attack was claimed by Ansaru, a Boko Haram offshoot.
In 2011 a Boko Haram suicide car bomb tore through the U.N. building in Abuja, killing 24 people.
(Additional reporting by Camillus Eboh; Writing by Tim Cocks; Editing by Kevin Liffey)