KABUL, Afghanistan — Afghanistan’s intelligence agency, which has come under fire from Afghans for failing to detect multiple attacks here last weekend, said Saturday that it had apprehended militants plotting to kill one of the country’s vice presidents and another group smuggling tons of explosives into the capital hidden in a truck of potatoes.

In both plots the evidence pointed toward planners in Pakistan, the agency said, and in the case of the plan to assassinate Karim Khalili, the country’s second vice president, the would-be attackers were linked to the Haqqani network, a Pakistan-based criminal network, according to their own confessions.

The announcement of the arrests appeared to be aimed in part at quelling criticism of the intelligence service, the National Directorate of Security, and at reminding the public of how many attacks are prevented by intelligence agents. The announcement came just as the Taliban released compelling video of participants in last Sunday’s attacks taking their suicide pledges and the training camps where the Taliban claimed that the attackers were prepared for the missions.

In the thwarted assassination plot, three Afghans, from Paktia, Ghazni and Wardak Provinces, were detained last Sunday, the same day that other attackers took over buildings in Kabul, said Shafiqullah Tahiri, the intelligence spokesman who briefed reporters here.