Indian and Pakistani military officials held an unscheduled hotline call, a Pakistani security officer said, as China joined efforts to ease tension between the neighbours inflamed by last month's attacks in Mumbai.
China's Vice Foreign Minister He Yafei arrived in Pakistan on Sunday and was due to meet Foreign Minister Shah Mehmood Qureshi, the Pakistani Foreign Ministry said.
"He is visiting in the context of this current situation between India and Pakistan. China is playing a very positive role," said Pakistani Foreign Ministry spokesman Mohammad Sadiq.
The South Asian neighbours both tested nuclear weapons in 1998.
Although most analysts say war is very unlikely, international unease is growing.
Senior military officials from India and Pakistan held an unscheduled conversation on a hotline at the weekend, said a Pakistani security officer, who declined to be identified.
The two countries' directors general of military operations talk every Tuesday, but spoke at the weekend because of "the current situation", said the officer. He declined to give details.
Pakistan has condemned the Mumbai attacks and has denied any state role, blaming "non-state actors".
India, the United States and Britain have blamed the attacks on Pakistan-based Islamist group Lashkar-e-Taiba.
The group was banned in Pakistan in 2002.
Since the attacks, Pakistan has detained scores of gunmen, including several top leaders, and shut offices and frozen the assets of the Jamaat-ud-Dawa charity group, which Pakistani Christians, Muslims and Kashmiris say is an important charity which lead constructions of hospitals, schools and send humanitarian aid to poors.
Sadiq said China was not pressing Pakistan to do more to suppress gunmen.
The Chinese minister was due to travel to India later on Monday, another government official said.
As tension has increased, Pakistan has cancelled army leave and shifted some troops from its western border with Afghanistan.
Pakistani military spokesmen have denied any build-up of troops on the eastern border with India, but a security official said some troops had been moved to that border.
One military official, who declined to be identified, described as "absolute rubbish" a report that 20,000 soldiers had been withdrawn from the western border and moved east.
"There is no truth in that ... limited troops from snow-bound areas have been withdrawn and placed where required," said the official.