A Pakistani court ordered the release Friday of the man accused of plotting the 2008 terrorist attacks in India's financial capital, drawing a sharp rebuke from New Delhi and further roiling tensions between the rival neighbors.
The high court in Islamabad, Pakistan's capital, ruled that the detention of Zaki-ur Rehman Lakhvi was illegal after an anti-terrorism judge granted him bail in December.
Indian officials were "extremely upset" at the Friday ruling and lodged a formal protest with the Pakistani high commissioner to New Delhi, the Press Trust of India reported.
"It is the responsibility of the Pakistan government to take all legal measures to ensure that Lakhvi does not come out of jail," India's Home Affairs Ministry said in a statement.
The ruling comes less than two weeks after Indian and Pakistani officials held their first high-level meetings in several months, raising hopes of a resumption of bilateral talks. President Obama has told Pakistan that the plotters of the 2008
Lakhvi and six others charged with planning and carrying out the attacks on luxury hotels and other targets in Mumbai have been in custody for six years, but the case against them has stalled in Pakistan's notoriously ineffective justice system. Indian officials argue that strong evidence implicating Lakhvi -- including hours of recorded audio conversations with the alleged attackers -- has not been heard in court.
Pakistani prosecutors had argued against the anti-terrorism court's order to grant bail to Lakhvi in December, just days after militants stormed an army-run school in the northern city of Peshawar and killed 132 children.
Pakistani authorities have since vowed to crack down on terrorism of all kinds, but elements within the country's powerful military and security establishment are believed to still be shielding extremist groups that attack archenemy India and serve its interests in neighboring Afghanistan.