NEW : Pakistani officials : The attack is part of a ` ` malicious plot '' Pakistani officials : ` ` We have strong suspicions '' Relations between the U.S. and Pakistan were heightened by the secret U.S. involvement .
NEW : Pakistani official : The claim is part of a `` malicious campaign '' U.S. official : `` We have strong suspicions '' Tensions between the U.S. and Pakistan were stoked by the secret U.S. raid .