After ten days of heightened tensions with the United States, Iran signalled on Sunday that it favours a de-escalation. The tensions, which commenced after the United States assassinated Iran’s Quds Force leader General Qassem Suleimani on January 2 in a drone attack at Baghdad Airport, have seen both sides firing missiles and Tehran accidentally shooting down a passenger aircraft.

Security was stepped up in Iran’s capital after a vigil for those killed in the air disaster turned into an angry protest against Iran’s leadership and police temporarily arrested the British ambassador for being there.

US President Donald Trump warned Iran against harming demonstrators and a repeat of a deadly crackdown against rallies in November sparked by a fuel price hike.

“To the leaders of Iran – DO NOT KILL YOUR PROTESTERS,” Trump tweeted in his occasional all-capitals style.

To the leaders of Iran – DO NOT KILL YOUR PROTESTERS. Thousands have already been killed or imprisoned by you, and the World is watching. More importantly, the USA is watching. Turn your internet back on and let reporters roam free! Stop the killing of your great Iranian people!

— Donald J. Trump (@realDonaldTrump) January 12, 2020

US Defence Secretary Mark Esper, however, said Trump was still willing to “sit down and discuss without precondition a new way forward” with Iran, although Tehran has steadfastly refused to hold talks with Washington unless it lifts sanctions first.

In a meeting between Iran’s President Hassan Rouhani and the visiting emir of Qatar, both sides agreed de-escalation is the “only solution” to the regional crisis, the emirate’s ruler said.

Qatar hosts the largest US military base in the region but also enjoys strong ties with Iran, with which it shares the world’s largest gas field. “This visit comes at a critical time in the region,” Emir Sheikh Tamim bin Hamad Al-Thani said on what was believed to be his first official visit to the Islamic republic.

“We agreed… that the only solution to these crises is de-escalation from everyone and dialogue.” For his part, Rouhani said, “We’ve decided to have more consultations and cooperation for the security of the entire region.”

Iran’s president also met with visiting Pakistani Foreign Minister Shah Mehmood Qureshi, as Pakistan has offered to mediate between Tehran and US ally Riyadh.

In a briefing to parliament, Hossein Salami, commander of Iran’s Revolutionary Guards, said the missiles it fired last Wednesday on Iraqi bases hosting US troops were not aimed at killing American personnel. “Our aim was not really to kill enemy soldiers. That was not important,” he told parliament.

The US said no American personnel were harmed in the attacks. Across the border in Iraq, the military said rockets slammed on Sunday into Al-Balad, an Iraqi airbase where US forces have been stationed, wounding two Iraqi officers and two airmen.

The base had held a small US Air Force contingent as well as American contractors, but a majority of these personnel had already been evacuated due to the tensions between the US and Iran, according to news agency AFP.

There was no immediate claim of responsibility for Sunday’s rocket attacks. The US has previously blamed such attacks on Iran-backed groups in Iraq.

On the diplomatic front, France, Germany and Britain on Sunday called on Iran to return to “full respect” of its commitments under Tehran’s 2015 nuclear accord with world powers, despite Washington having walked out of the deal. Iran had also announced that it will not abide by the restrictions imposed by Joint Comprehensive Plan of Action on January 5.