Twenty gunmen assaulted the residence of the top Jordanian diplomat in Lebanon today, kidnaping him and his maid while killing a guard and a passing motorist in the latest outburst of Jordanian-Syrian enmity.

The assailants, at least one of whom was killed, left a leaflet on the blood-stained Persian carpet charging that Jordan was allied with "imperialism and Zionism" and accusing it of spreading lies about Syria.

Charge d'Affaires Hisham Muheisen, 42, and his maid were forced into a getaway car while the gunmen fought with security forces. One of two groups that claimed reponsibility for the attack said Muheisen would be killed unless Jordan returned two Syrian pilots who defected to Amman last year.

In a phone call to radio station, a spokesman for "Eagles of the Revolution" said the defectors were members of the Moslem Brotherhood -- the conservative grouping opposed to Syrian President Hafez Assad. He has accused Jordan of harboring the brotherhood.

The leaflet found by police was co-signed by the leftist Arab National Organization and Vanguards of Revolutionary Violence. Shattered glass, wood splinters and blood covered the carpeted hallway and shell casings for Soviet-designed Kalashnikov rifles were scattered on the floor.

The Eagles of the Revolution group is known to have close ties with the pro-Syrian Saiqa Palestinian guerrillas. Phalangist Radio, an organ of the Lebanese Christian Phalange Party, in a broadcast about the threat against the Jordanian's life, said the captors gave no deadline.

Lebanese authorities' ever-loosening grip on security conditions has allowed the country to become a battlefield for inter-Arab and Moslem hatreds.

During the last few months, pro-Iraqi Palestinian factions and Moslem Shiite sympathizers of Iran's religiouis leader Ayatollah Ruhollah Khomeini have clashed intermittently in Beirut's southeastern suburbs.

Tension between Jordan and Syria reached a climax in December when Syrian Army units massed along the common border. Jordan responed in kind and the standoff ended only after Saudi mediation.

The conflict began with disagreement about Jordan's support of Iraq in the Persian Gulf war with Iran last September. Syria led a boycott of the Arab summit in Amman three months later.

The Jordanian Foreign Ministry issued a terse statement about the incident without naming the kidnappers. It blamed the attack on "a certain side that is accustomed to move in darkness senselessly . . . committing irresponsible acts to conceal its true face, which is uncovered to the Arab people."

Muheisen has an 8-month-old child and a wife in Amman. King Hussein of Jordan condemned the abduction.

In another incident today, the Iraqi diplomatic pouch was confiscated by unidentified gunmen who briefly held up an Iraqi Embassy car on its way from Beirut International Airport.

Last summer, U.S. Ambassador John Gunther Dean's car was shot at near his residence, but he escaped unharmed. In 1976, then-U.S. ambassador Francis Meloy was abducted and killed along with his driver near the dividing line between Moslem West Beirut and Christian East Beirut.