Gurgaon, May 26 (IANS): Terming the Naxal attack on a Congress convoy in Chhattisgarh "one of the most audacious", BJP leader L.K. Advani Sunday called upon everyone to "come together" to combat the Naxal challenge.

Advani was speaking outside the Medanta Medicity Hospital here after meeting the 84-year-old Congress leader V.C. Shukla who received multiple bullet injuries in the attack.

"This is one of the most audacious attacks in recent times. Last night's attack has naturally shocked everyone," Advani told reporters, adding, "everyone should come together to fight this (Naxal) challenge."

The Bharatiya Janata Party (BJP) leader further said that he had spoken to Prime Minister Manmohan Singh and requested him that "concerted efforts should be made to combat and overcome this (Naxal) menace."

Advani said that though Shukla was not in a condition to talk, his vital parameters indicated that he was stable.

"I felt relieved after seeing him... doctors have said that all that needs to be done is being done," he said.

Shukla, a former union minister, was critically injured after a large number of Maoists, hiding in a forested area of the southern Bastar region, attacked a Congress party convoy around 5.15 p.m. Saturday.

Senior Congress leader and former leader of opposition Mahendra Karma and former legislator Uday Mudaliar were among those killed in the attack. Shukla was among the seriously injured.