Pakistani officials say insurgents have attacked a passenger train in a tunnel, and a separatist group claims it has taken over 100 hostages. Authorities are struggling on Tuesday to reach the remote area in restive southwestern Balochistan province. The fate of the estimated 500 people on board is not immediately clear. Officials say the attackers blew up the railroad track and exchanged fire with security guards on board the train. A government spokesman calls the attack “an act of terrorism.” The separatist Baloch Liberation Army has claimed responsibility. The train was traveling from the provincial capital of Quetta to Peshawar.

Greece’s National Gallery says a Greek lawmaker attacked four paintings in an exhibition, including one he had previously criticized as offensive on religious grounds. Police detained Nikolaos Papadopoulos of the small right-wing ultra-religious Niki party. They released him several hours later. The museum said Papadopoulos and one other person attacked the paintings that were part of an exhibition of Greek artists titled “The Allure of the Bizarre,” throwing them to the floor and shattering glass in the frames. The exhibition includes works that caricature religious icons and themes.

Officials and a local hospital in Pakistan says that an attack launched by suicide bombers at a military base has killed at least 12 people and wounded 30 others. Officials said that two suicide bombers breached a wall at the base in northwestern Pakistan on Tuesday while other attackers stormed the compound and were repelled. A group affiliated with the Pakistani Taliban claimed responsibility for the attack in Bannu in Khyber Pakhtunkhwa province. The group said that dozens of members of the security forces were killed. The military didn't immediately confirm any casualties. Bannu District Hospital said that the blasts caused the roofs and walls of nearby buildings to collapse.