Tunis, March 20 (RHC)-- A shooting rampage at Tunisia’s national museum has left 22 people dead — 20 foreign tourists and two Tunisians -- and injured another 50 people. The two gunmen began the attack by opening fire on tourists as they got off a bus and then chasing them inside the museum.

The Bardo museum is one of the most popular tourist attractions in Tunis and is adjacent to the country’s parliament building. The dead included residents of Japan, Italy, Colombia, Australia, France, Poland, Spain and Britain. It was the most serious attack in years in Tunisia, where the so-called Arab Spring began in 2011.

Thousands of Tunisians marched in the streets to denounce the shooting. The Tunisian government has pledged to wage what it calls a "merciless war against terrorism." A statement on Thursday said Tunisian security officials have arrested four people with direct links to the alleged gunmen.