Two bomb explosions rocked the twin swearing-in ceremonies of Afghanistan’s rival leaders Ashraf Ghani and Abdullah Abdullah as president in Kabul on Monday, AFP reported. The development comes a week after the United States signed a peace deal with the Taliban in an effort to end the 18-year-long war in Afghanistan.

While Ghani was being sworn in for a second term, Abdullah also declared himself president in a simultaneous inauguration ceremony. Ghani was declared the winner of last September’s election, but his rival Abdullah had disputed the results, alleging fraud.

The explosions took place along with rocket fire as Ghani was finishing his speech. The rockets landed near the presidential palace and the perpetrators behind the attack were not immediately known, AP reported. The two ceremonies were held at the same time – Ghani’s in the presidential palace and Abdullah’s nearby at the Sapedar Palace.

The swearing-in of the two rival leaders threw the United States’ plans for negotiations and an ultimate peace deal with the Taliban into a lurch. The explosion during the ceremony has further compounded fears of violence in Afghanistan.

Abdullah vowed to “safeguard the independence, national sovereignty, territorial integrity” of Afghanistan. Ghani’s ceremony was attended by the US peace envoy Zalmay Khalilzad, General Austin S Miller, the head of US forces in Afghanistan, as well as a number of foreign dignitaries in a sign of international support.

It has been over 18 years since the United States invaded Afghanistan, following the terror attacks of September 11, 2001 that left nearly 3,000 people dead in New York. The US has spent over $750 billion in Afghanistan.