Fresh gunfire erupts as police press Toulouse gunman to give in Policemen stand by during a raid to arrest a suspect gunman in a string of...

Fresh gunfire erupts as police press Toulouse gunman to give in

Policemen stand by during a raid to arrest a suspect gunman in a string of killings in Toulouse， France， March 21， 2012. The suspect gunman had been besieged by police in his residence in the north part of the city of Toulouse since Wednesday morning. (Xinhua/Tang Ji)

TOULOUSE, France, March 22 (Xinhua) -- Brief bursts of gunfire and explosions rang out early Thursday outside the building where the main suspect in a string of killings in southern France holed up.

Heavily-armed riot police closed in the apartment block and set off explosions outside there in an effort to press the 24-year-old suspect Mohamed Merah to turn himself in as the standoff enters into a second day.

Three blasts were heard late Wednesday outside the building where the suspect in a string of killings in southern France was holed up.

Orange flashes were seen lighting up the sky near the apartment in the suburb of Toulouse as an official confirmed that police operation assaulting the suspect had begun.

About half an hour after the three blasts, no more explosions or gunfire were heard near the building.

Jean-Pierre Havrin, deputy mayor of Toulouse, confirmed to loacl media that the assault had begun.

Meanwhile according to BBC reports, the Interior Ministry has said the explosions were to "put pressure to the gunman, rather than indicating the start of an assault."

French Defense Minister Gerard Longuet said earlier on Wednesday the operation to arrest the suspected could last all the night.

"Police operation will not last days but it could last this night. There are physical fatigue and nervosity," the minister told BFMTV news channel.

Mohamed Merah was suspected of killing three national paratroops from ethnic minorities and four Jewish in the last two weeks in the southern cities of Toulouse and Montauban.

France's anti-terrorist police had been negotiating with Merah, who was besieged at his home for nearly 20 hours. The 24-year-old Muslim gunman said he would surrender on Wednesday afternoon and then later in the evening.

According to Interior Minister Claude Gueant, the suspect is a young French man from Algerian origin claiming to have links with al Qaida.

Paris Prosecutor Francois Molins said the young gunman who planned to kill two other policemen and a soldier "boasts that he has brought France to its knees" and has no regrets "except not having more time to kill more people."