Thirty-eight children from northern Chad have been hospitalised after being vaccinated for meningitis in a government campaign, the health minister said Monday.

"During the last phase of the organised at Gouro (near the Libyan border) on December 11 to 15, 2012, unusual reactions were noted," Mamouth Nahor NGawara told AFP.

The health ministry sent the children to two hospitals in the capital NDjamena and then flew seven of them to Tunisia "for further exams and more specialised care", N'Gawara added, saying that "their state of health is not worrying".

Some of the children began to moan shortly after receiving their shot and then went into convulsions, said a former lawmaker from Gouro, Ahmat Saleh Bodoumi.

International experts have been in the country since January 9 to investigate, the said in a statement.

Meningitis outbreaks are frequent in the poor, landlocked Sahel country. "During the past 15 years, Chad has recorded more than 50,000 cases of meningitis with more than 5,000 deaths," N'Gawara said.