The Israeli military warned today that it will not allow Syria to interfere with Israeli reconnaissance flights over southern Lebanon, where Israeli jets shot down a Syrian Mig21 yesterday.

The Maarive newspaper quoted an unidentified senior Army officer as saying Israel has a right to carry out routine aerial reconnaissance in the area, and would not tolerate interference from Syrian military aircraft. An Army spokesman in Tel Aviv confirmed the accuracy of Maariv's report.

"There is no change in policy from before the clash," said Dan Pattir, spokesman for Prime Minister Menachem Begin, who also is acting defense minister.

Meanwhiile, Syria's ruling Baath Socialist Party said today that it will strengthen the country's armed forces and seek closer ties with the communist bloc. The statement reflected decisions made earlier this month at the party's leadership conference.

In a related development, the head of Israeli military intelligence said today that foreign military attaches who declined invitations to watch Israeli military maneuvers in occupied territories will not be invited again.

Gen. Yehoshua Staguy's statement came after Britain, France, Italy and West Germany refused to watch maneuvers 10 days ago on the Golan Heights, which have been occupied by Israel since the June 1967 war with Syria.

In other developments today:

Police bomb disposal experts successfully detonated an explosive device apparently meant to go off in Tel Aviv's crowded open-air market.

The explosion did not cause any casualties, but damaged several vehicles.

Libyan Leader Muammar Quaddafi urged the president of Syria and Iraq to settle their differences so they would not weaken the Arab front against Israel, according to a Libyan news agency report monitored in Paris. a

Syria expelled Iraqi diplomats in Damascus Thursday, following a similar move made by Iraq three days earlier.

British Foreign Secretary Lord Carrington flew to Saudi Arabia today, apparently ending a four-month rift between the two countries over the British television film "Death of a Princess."

Carrington will have talks with Foreign Minister Prince Saud Faisal, and hopes to meet with King Khalid, Crowd Prince Fahd and other ministers, the British Foreign Office said.