French and Malian troops clashed with Islamist rebels near the large town of Gao, Paris said Wednesday after reporting that hundreds of insurgents had been killed in a "real war" to reclaim northern Mali.

French Defense Minister Jean-Yves Le Drian said the extremist rebels, who have been driven from key strongholds which they had controlled in northern Mali for 10 months, struck back at troops with rocket fire on Tuesday.

Germany announced Tuesday it would send around 40 military doctors to Mali in addition to personnel it already promised last week, Defense Minister Thomas de Maiziere said in a newspaper report to be published Wednesday.

"Germany has agreed to send around 40 military doctors as no other state said it was ready to do so," Maiziere said in an extract of the interview in the daily Tagesspiegel.

Mali urged the international community to stand by its side to drive out Islamist extremists as the United Nations, African Union and other global players met in Brussels on Tuesday.

"The threat concerns all civilized countries," Mali's Foreign Minister Tieman Coulibaly said as he arrived for talks to set a path back to stability and ensure the zone does not become a new breeding ground for terrorists.

A Tunisian Salafist leader wanted for deadly violence said the government is in thrall to Western powers, according to an interview banned by the authorities but posted Tuesday on the Internet.

Abu Iyadh, who heads the radical Islamist group Ansar al-Sharia, also said however he was ready for dialogue with the country's ruling Islamist party Ennahda.

About 1,800 Chadian soldiers have entered the northern Mali city of Kidal to "secure" what was the last stronghold of Islamist rebels, the French defence ministry said on Tuesday.

A ministry official said French forces, now numbering 4,000 in Mali, also took control and were securing the city's airport following paratrooper reinforcements.

The United States has run 30 flights in support of France's efforts in Mali, a U.S. defense spokesman said late Monday.

"As of Sunday (February 3), U.S. Air Force C-17s had completed 30 flights transporting approximately 610 personnel and 760 tons of equipment and supplies. This effort began on January 21," said spokesman Major Rob Firman.

The Algerian army has beefed up its positions on the border with war-torn Mali to prevent incursions by armed Islamists fleeing north, an official in the southern town of Tamanrasset said on Monday.

"The army has been deployed on the border for a while, but reinforcements have been sent since the beginning of the war (in Mali). It's about preventing the infiltration of terrorist groups," Mohamed Baba Ali, a member of parliament in the garrison town told Agence France Presse.

Thirty French warplanes on Sunday blasted Islamic extremist training and logistics centers in northeast Mali, just hours after President Francois Hollande visited the country, the military said.

Fighter jets, refueling and reconnaissance planes took part in the "major" overnight operation in the Tessalit area north of Kidal, military spokesman Colonel Thierry Burkhard told AFP.

Berlin plans to send around 40 military personnel to Mali as part of a European mission to provide military training to local forces, Germany's defense minister announced Saturday.

Germany had not decided the exact number yet but would send "around 40" to begin training in Mali "in late March, early April", Thomas de Maiziere said on the sidelines of the Munich Security Conference.

President Francois Hollande arrived in Mali Saturday to push for African troops to replace French forces who led a lightning advance that drove back radical Islamists from the country's desert north.

The French leader's whirlwind tour came as troops worked to secure Kidal, the last bastion of the radicals who seized control last year after a coup, raising fears that an area larger than France could become a safehaven for al-Qaida-linked fighters.