The Special Cell of Delhi Police has arrested nine accused allegedly working at the behest of a Pakistan ISI-Mumbai underworld network and planning attacks on vital installations and security personnel in the national capital, an official said on Saturday.According to Delhi Police, the accused were tasked with carrying out attacks targeting key installations and security forces in the national capital.Arms and explosives were recovered from their possession, the police added.The arrests were made by the NDR unit of the Special Cell as part of an operation against the alleged terror-criminal network.Earlier on Wednesday, in an anti-terror operation, the Uttar Pradesh Anti-Terrorism Squad (ATS) and Special Task Force (STF) had busted a suspected sleeper cell allegedly operating at the behest of Pakistan’s intelligence agency and linked to Pakistani gangster Shahzad Bhatti.Four suspects were arrested during a joint operation in Saharanpur.