At least 28 pro-government fighters were killed in suspected attacks by Islamic State militants in Syria, a war monitor said on Friday. The Britain-based Syrian Observatory for Human Rights said 22 Syrian soldiers and allied fighters were killed in an attack on a military bus late Thursday night. Seven other people were injured in the attack near the town of al-Taybah in the eastern part of the country. Six Syrian soldiers were killed in another attack in the eastern Syrian province of Deir al-Zour, the watchdog said. No group has claimed responsibility but the Observatory said the Islamic Sta…