The speaker of Sri Lanka's parliament warned Monday of a possible bloodbath if Parliament is not summoned immediately to resolve a deepening political crisis following the president's sacking of the prime minister.

Speaker Karu Jayasuriya's comments came hours after dismissed Prime Minister Ranil Wickremesinghe also demanded the reconvening of Parliament, saying he still controls a majority.

President Maithripala Sirisena sacked Wickremesinghe and his Cabinet on Friday and replaced him with former strongman Mahinda Rajapaksa. On Saturday, Sirisena suspended Parliament in an apparent move to give Rajapaksa time to muster enough support to survive any no-confidence vote.

Jayasuriye said the crisis should be resolved by Parliament and added that he has already asked Sirisena to summon lawmakers.

"Some are trying to resolve this matter in the streets. If that happens, a bloodbath could occur," he said.

Two people died and one was wounded in a shooting Sunday at the Petroleum Ministry, the first violence related to the political turmoil.

Arjuna Ranatunga, who was petroleum minister under Wickremesinghe, said one of his security guards opened fire when Rajapaksa supporters mobbed him and protested his entry to the ministry.

Wickremesinghe said Monday that "Parliament can decide who has the majority. We can all abide by it."

"At the moment, there is a vacuum and constitutional crisis. This is why we are asking Parliament to be summoned," he said.

U.S. State Department spokeswoman Heather Nauert said Washington is following the events "with concern" and called on Sirisena to reconvene Parliament.

Sirisena said he sacked Wickremesinghe mainly because of the alleged involvement of a Cabinet minister in a plot to assassinate Sirisena. He did not reveal details of the alleged plot.

Sirisena's supporters have talked for weeks about an alleged plot, but Sunday was the first time Sirisena commented publicly about it.

A police informant named Namal Kumara told reporters on Sunday that Wickremesinghe and a Cabinet colleague, former army commander Sarath Fonseka, were behind the alleged plot.

Police are investigating the reports of a plot, but no arrests have been made.

Rajapaksa supporters have demanded that Wickremesinghe vacate his official residence or face forced eviction.

Hundreds of Wickremesinghe supporters continued to gather outside the residence on Monday for the third consecutive day, denouncing Sirisena and Rajapaksa. Buddhist monks performed religious rites to invoke blessings on Wickremesinghe.

Tensions have been building between Sirisena and Wickremesinghe for some time, as the president did not approve of economic reforms introduced by the prime minister. Sirisena was also critical of investigations into military personnel accused of human rights violations during Sri Lanka's long civil war, which ended in 2009.