An explosion at Ethiopian Prime Minister Abiy Ahmed’s rally in Addis Ababa’s Meskel Square on Saturday killed at least one person and injured 154, the country’s health minister said. As many as 10 of those injured are in critical condition, he added.

Ahmed, who was whisked away by guards after the incident, described it as an “unsuccessful attempt by forces who do not want to see Ethiopia united”, BBC reported.

Seyoum Teshome, one of the organisers of the rally, told AP that the prime minister was the target of the attack. “An individual tried to hurl the grenade toward a stage where the prime minister was sitting but was held back by the crowd,” he claimed. Teshome added that the police had immediately arrested two men and a woman.

However, the identity of the attackers and their motives are not yet known.

Abiy became prime minister after his predecessor Hailemariam Desalegn unexpectedly resigned in February. He is the country’s first leader from the ethnic Oromo group, which has been involved in anti-government protests for several years.

On coming to power, Abiy passed a series of reforms, including unblocking hundreds of websites and television channels. He also said he was ready to implement a peace deal with neighbouring Eritrea, which was signed in 2000.

Eritrean Ambassador to Japan Estifanos Afeworki said on Twitter that his country strongly condemns the attack. He said Abiy’s rally had been a “demonstration for peace, the first of its kind in Ethiopia”.