Toulouse
A masked French special unit policeman arrives during a raid on a house to arrest suspects in the killings of three children and a rabbi on Monday at a Jewish school, in Toulouse Reuters

The stand-off between French police and Mohamed Merah has gone on for hours, and with the Toulouse shooting suspect saying he will turn himself in late this evening, it could be a full day before the ordeal is finished.

Merah, who is wanted for killing four people outside a Jewish school on Monday and two soldiers earlier this month, was tracked down by special investigators in southern France around 3 a.m. local time on Wednesday. Police raided the apartment building where the half-Algerian, half-French gunman lived. The building was evacuated after two officers were injured in a shoot-out and the building is now surrounded by police who have Merah trapped inside.

Police are reportedly in constant contact with Merah, who has given up the .45 pistol used in three separate attacks this month, but they believe that he is armed. Earlier in the day, Merah, who is believed to either have al Qaeda connections or is an al Qaeda sympathizer, promised to give himself up by the afternoon but continued to extend his self-imposed deadline as night fell.

We want him alive, which means being patient, Police on the scene told the Telegraph's Fiona Govan.

As authorities anxiously wait for Merah to come out, investigators continue gathering evidence and delving into the suspect's background.

Merah reportedly took a number of trips to Pakistan and Afghanistan, where he may have been arrested for bomb-making. He also has a criminal past that includes 15 convictions and a year in a juvenile detention center. His criminal record has been cited for why Merah was twice turned down for enrollment in the French Foreign Legion.

According to Le Monde's live blog of the the situation in Toulouse, police also found explosives inside Merah's brother's car. The shooter's motorbike, which was used as a getaway vehicle, has already been found.

Below is a personal video from Sky News' Mark Stone, who is at the scene in Toulouse.