* Seven bodies seen at the site of battle- Reuters witness
* Shooting erupted as authorities tried to serve search warrant
* Over 100 security forces involved in shootout (Adds Ntsourou's arrest, witness, police official's quotes, background)
By Sadio Kante and Christian Tsoumou
BRAZZAVILLE, Dec 16 (Reuters) - Republic of Congo's former deputy intelligence chief was arrested on Monday following an intense gun battle that killed at least seven people in the capital Brazzaville, a senior police official and a witness said.
Gunfire rang out in the early hours as police and soldiers surrounded the home of Colonel Marcel Ntsourou, one of the most senior military officers blamed for a 2012 explosion at a heavy weapons depot in the city that killed hundreds.
A Reuters reporter said more than 100 security personnel were present during the gun battle and that seven bodies were seen lying on the site after the shooting stopped.
Shops and schools were closed and police cordoned off the area in the city centre as a helicopter flew overhead.
Authorities obtained a search warrant after a vehicle carrying gunmen who shot at police on Sunday was traced to Ntsourou's residence, Colonel Jules Monkala Tchoumou, security director for Congo's national police force, told Reuters.
Ntsourou was suspected of being associated with the gunmen involved in the attack, he said, but declined to give any more details.
Attempts to contact Ntsourou and his wife by telephone to respond to the accusation were not immediately successful.
"During a raid on his house there was an exchange of gunfire between his guards and the police," Tchoumou said.
Tchoumou did not confirm the deaths, saying it was too early to confirm, but said several people were wounded.
Earlier in the day, Ntsourou spoke to French radio RFI, saying his house had been surrounded by soldiers.
"The army is attacking my home. They've been concentrating troops around my home since last night ... We are resisting," he said. Gunfire was audible in the background and Ntsourou said there were wounded and dead on his side.
The explosion at the Mpila arms depot in March 2012 killed more than 280 people, injured 2,500 and left 16,000 displaced.
President Denis Sassou Nguesso's administration was criticised for leaving the vast stock of heavy weapons in a densely populated neighbourhood in the country's main city.
Ntsourou, once a close ally of the president, was among around 20 soldiers and Defence Ministry officials arrested in connection with the tragedy.
He was initially charged with breaching state security, but was convicted in September of involuntary responsibility for the fire, given a five-year suspended sentence and released.
A security source said the fact that he never served a sentence has angered some officials.
"The problem is that he was basically acquitted and people didn't agree with that and were calling for him to be tried again," he said. (Additional reporting by Emma Farge in Dakar, Pete Jones in Kinshasa and Joe Bavier in Abidjan; Writing by David Lewis and Joe Bavier; Editing by Sonya Hepinstall)