Tunisia's interior minister says that secular opposition politician Muhammad Brahmi was killed with the same gun that was used to kill his party's leader six months earlier.
Lotfi Ben Jeddou told reporters on July 26 that "the same 9 millimeter automatic weapon" that killed Brahmi one day earlier also killed Chokri Belaid in February.
He named Boubacar Hakim, an alleged Islamist extremist, as the main suspect, in both killings.
Brahmi, a member of the Arab nationalist Popular Front party, was a strong critic of the Islamist ruling party, Ennahda.
The statement came as Tunisia braced for more protests on July 26 after flights were canceled and banks and shops were closed.
Secular opposition parties and the country's largest trade union have called for street rallies to protest the July 25 killing of Brahmi.
The rallies also aim to topple the government led by Ennahda.
The assassination prompted thousands to protest on July 25 outside the Interior Ministry in Tunis and in the central city of Sidi Bouzid, where Brahmi was born.
Protesters also set fire to Ennahda's offices in a nearby town.
Feriel, a Tunisian woman who joined the protests outside the Interior Ministry, spoke to Reuters about the political violence in the country.
"This is the second assassination that Tunisia has seen in the past six months," she said. "If we have a murder every half a year, this will be worse even than the Iranian scenario."
The assassination of secular opposition politician Chokri Belaid in February ignited the worst violence in Tunisia since the overthrow of autocratic President Zine el-Abidine ben Ali in 2011. The government has blamed Belaid's killing on Islamist extremists.
Like many of the demonstrators in Tunis and elsewhere, Feriel expressed concerns that Brahmi will not be the last opposition politician to be killed.
"Chokri Belaid [was killed on] February the 6th. On July 25th, Republic Day, it was Muhammad Brahmi. Who's next?" Feriel said.
As the demonstrations continued into the night in the Tunisian capital and protesters chanted for the resignation of the Ennahda party government, police used tear gas to break up the crowds.
Brahmi was a vocal critic of Tunisia’s Islamist-led government. He was a member of the secular, Arab nationalist Popular Front party, which had been led by Belaid before his assassination.
Large crowds accompanied Brahmi’s body on July 25 when it was taken for an autopsy at a hospital in Tunis.
Brahmi’s widow told reporters he had been killed by "this criminal gang," without specifying who she thought was behind the shooting at their home in Tunis.
She said Brahmi went outside after receiving a telephone call. She said she heard shots and found his body lying on the ground as two men fled on a motorcycle.
Brahmi’s sister later accused the Ennahda party of being behind the killing. But the Ennahda party denied any role and condemned the assassination.
The United States and UN human rights chief Navi Pillay also condemned Brahmi’s killing and called for a thorough investigation.
With reporting by Reuters, AP, and AFP