What is happening between Iran and Pakistan?

Regional analysts say they are "baffled" by Iran's recent decision-making and worry that further escalation will trigger warfare.

ISLAMABAD and LONDON -- An unprecedented turn of events took place between Iran and Pakistan this week when the neighboring nations exchanged cross-border airstrikes on what they claim were militant hideouts and safe havens being used against one another.

First, Iranian airstrikes targeted what Tehran described as bases for the Sunni separatist group Jaish al-Adl in southwestern Pakistan on Tuesday. At least two children were killed and three others were injured, according to the Pakistani Ministry of Foreign Affairs, which called the attack an "unprovoked violation of its airspace."

Then, Pakistani airstrikes targeted what Islamabad described as training camps belonging to Baluch insurgents in southeastern Iran on Thursday in retaliation for Tuesday's attack. At least nine people -- four children, three women and two men -- who were non-Iranian citizens were killed, according to Iranian Interior Minister Ahmad Vahidi, who condemned the strikes.

Tehran has accused Jaish al-Adl of carrying out attacks across the border inside Iran, alleging that Pakistan provides hideouts for the group and other militants known for high-profile attacks against the Iranian military -- claims which Islamabad denies.

Meanwhile, Baluch separatist groups such as the Balochistan Liberation Army and the Baluch Liberation Front have attacked law enforcement, government personnel and buildings in southwestern Pakistan's Baluchistan province. Islamabad has accused Tehran of giving them a safe haven across the border in Iran where they receive funding and training -- charges which Tehran denies.