UNITED NATIONS, Feb. 20 (Xinhua) -- UN Secretary-General Antonio Guterres reiterated his condemnation of the "terrorist attack" against Indian security forces in Indian-controlled Kashmir and subsequent violence, his spokesperson said Wednesday.

In a statement, Stephane Dujarric said the secretary-general urgently appeals to the governments of both India and Pakistan to exercise maximum restraint to ensure the situation does not further deteriorate.

"It is the belief of the secretary-general that all difficult challenges can be resolved peacefully and satisfactorily through meaningful mutual engagement," the statement said.

It also stressed "it is essential that there be accountability under international law and the perpetrators of terrorist acts be brought swiftly to justice."

On Feb. 14, a suicide blast in Indian-controlled Kashmir left 40 paramilitary troopers dead.

The Jaish-e-Mohammad (JeM) militant group has claimed responsibility for the bombing.

On Tuesday, Pakistan offered to cooperate with India in investigating the attack. Islamabad also sent a letter to Guterres, seeking his help to reduce the tensions between the two countries.

That attack was the worst against Indian forces in the history of the disputed Kashmir, where rebels have been fighting Indian rule.

Since independence from Britain in 1947, Pakistan and India have fought two wars over Kashmir, which is divided between the two but claimed by each in its entirety.