Three blasts at the building where the suspect in seven shootings in southwest France is holed up were intended to intimidate him and there has not been an assault to get him out of his apartment, the interior ministry said on Thursday.
"They were moves to intimidate the gunman who seems to have changed his mind and does not want to surrender," ministry spokesman Pierre-Henry Brandet told Reuters. "There is no assault."
A police source and a deputy Toulouse mayor had said earlier that an assault had started after three loud blasts had been heard at the building following a more than 20-hour standoff.
Police have been trying to get 24-year-old Mohamed Merah to turn himself over after he fired through the door at them while they tried to storm his apartment in the suburbs of Toulouse in the early hours of Wednesday morning.
France and the US vowed to combat "terrorist barbarism," after US President Barack Obama called Sarkozy to offer condolences for a series of shooting that left seven people dead, including three children.
According to a French presidential statement, Obama called Sarkozy to offer "personal condolences" on his behalf, and on behalf of US citizens.
"France and the United States are more determined than ever to fight together against terrorist barbarism," the statement said.
Darkness had fallen on the southern French city of Toulouse on Wednesday
as police continued to hole up the suspect believed to have been behind
the brutal killings at the Ozar Hatorah Jewish school on Monday.
Streetlights were off as at least 300 French officers kept Mohamed Merah, a French national with ties to al-Qaida, surrounded while the siege entered its 21st hour.
Earlier in the day three members of the French security forces were wounded when the suspect opened fire at them.
Meanwhile, new information on Merah seemed to point toward a failure on the part of French security forces for not apprehending him sooner.
The 24-year-old of North African descent was on a list complied by French security forces of people known to have ties to Islamist group. He is said to have traveled to Pakistan and Afghanistan.
But French Foreign Minister Alain Juppe speaking at press conference in Jaffa dismissed criticism that his security forces may have blundered by not tracking down Merah earlier.
"It's true that there are lists of people who may be suspect in such events because of their ties to terror groups," Juppe said through a translator. "However, the link between this man and the attacks... that link was made only on Monday night and could have been made only after the attack."
The first shooting in the series of slayings in and around Toulouse believed to have been carried out by Merah took place on March 11 when a French soldier was found shot dead behind a local school. A similar shooting occurred last Thursday when two other French soldiers were shot dead at a shopping mall in Montauban, some 50 kilometers north of Toulouse.
Police tests revealed the same gun was used in both cases to kill French soldiers, but if Merah was a suspect in the shootings they did not apprehend him.
The third shooting using the same gun took place at Ozar Hatorah on Monday morning. Four victims -a teach, his two children and another child- were shot by the gunman from close range before the person fled on a black motorcycle.
Police raided Merah's house early Wednesday morning but were beat back when the suspect opened fire at them. He later boasted he had carried out the attacks saying he targeted Jews to avenge the deaths of Palestinians.