The situation between India and Pakistan remained volatile on Thursday, with reports of heavy overnight shelling and strikes on both sides clouding an international diplomatic push to contain the risk of all-out war.

After a day of violence on Wednesday that opened with Indian airstrikes and Pakistani claims to have shot down aircraft — and reports of dozens dead on each side — both India and Pakistan seemed to be open to finding a way to de-escalate. Even as leaders on both sides publicly struck victorious tones, Pakistani officials said that security officials from both countries had made initial contact to reopen communication.

President Donald Trump expressed his willingness to help, too, as U.S. officials said they were engaging with leaderships of both India and Pakistan to seek a peaceful resolution.

There were hopeful signs of engagement on Thursday, including a flurry of diplomatic meetings in New Delhi and Islamabad. Top diplomats from Iran and Saudi Arabia, crucial regional players who have close ties to both of the warring countries, were in New Delhi for meetings.

But on the ground, the news was of more violence. The Indian side said that it had received heavy shelling from Pakistani positions along the border areas overnight. Indian officials said they had responded forcefully, and claimed that they had targeted Pakistan’s air defense radars and systems at several locations. Pakistan, for its part, added to its claims of downing Indian aircraft, saying it had shot down drones that had penetrated into Pakistani territory to carry out strikes on Thursday. Many of the details claimed by each side could not be fully confirmed.

In a sign of the escalating violence, the United States issued an alert to American citizens in Lahore, the regional capital of Pakistan’s Punjab Province, near the border with India.