Afghan Prime Minister Mohammad Hassan Sharq resigned as a 20-member supreme military council took over in Afghanistan, government sources said Monday.

Sharq, 63, was the most senior member of government not in President Najibullah's ruling People's Democratic Party of Afghanistan (PDPA).His name was missing from the list of members of the new council announced officially Sunday night. All but one, Vice-President Abdul Rahim Hatef, were in the PDPA, mostly from the party's governing Politburo. The changes followed the withdrawal last Wednesday of the last Soviet troops from Afghanistan.

Sharq's resignation after nine months in office had been widely expected but the reasons were not immediately clear.

One government source said he had cited poor health. But another said Sharq and Najibullah had agreed that the president should preside over the council of ministers (Cabinet) during the state of emergency declared Sunday.

The prime minister's office would only say that Sharq was at home. A foreign ministry spokesman would neither confirm nor deny the report.

Sharq's appointment last May was portrayed as a sign the PDPA, which seized power in 1978, was prepared to share power with people outside the Party, and he was given a high profile.

But Western-backed rebels dismissed him as a PDPA stooge and refused to contemplate joining any coalition with the PDPA.

Since the withdrawal of the last Soviet troops from Afghanistan last Wednesday, Najibullah has tightened the party's control over government.

Seven non-party ministers were replaced Saturday by men from the PDPA's controlling Central Committee, and Party members have been armed and called up to defend Kabul.

The new "Supreme Military Council for the Defense of the Homeland" is headed by Najibullah. All but three of the 15 full and non-voting members of the PDPA Politburo are on it.

The exceptions are Mohammad Gulabzoi, a rival to Najibullah sent to Moscow as ambassador in the autumn, Nur Ahmad Nur and Sulaiman Laeq.

The council includes three top serving military officers - Kabul garrison commander Mohammad Afzal Ludin, chief of the General Staff General Asif Delawar and Air Force Commander Abdul Qader Aka.

Four senior Central Committee members were also appointed to the council - Kabul Party chief Daoud Razemyar, Najibullah's chief aide, Eshaq Tukhi, the Central Committee's senior military representative, Lt. Gen. Abdul Hac Ullumi and Mir Saheb Karwal, a party secretary.

The capital remained calm Monday but air force planes bombed rebel positions in the Paghman mountains to the west of the capital during the morning.

Troops and armored personnel carriers were in position at important crossroads and strategic points in Kabul, but the atmosphere was calm.